Cubicase Tutorial

What is Cubicase

Cubicase is a Windows program that creates, runs and shares Minecraft servers without you having to touch your router.

The idea in one sentence

Normally, to play with friends on a home server you need to open ports on your router, find out your IP, configure the firewall and install Java. Cubicase does all of that for you: it downloads the right Java, installs the server, and connects you and your friends directly over the internet, without opening any port.

The two roles

You can be both: host a server of your own and also keep your friends' servers in your library.

How the pieces fit together

1. The host creates a server (Minecraft version, type, memory) and starts it.
2. Cubicase connects the server to your friends automatically and generates an invite code in the format CF-XXXX.
3. The host sends the code (or a link) to friends.
4. The guest pastes the code in the Guest tab, clicks Prepare and Play, and Cubicase takes care of the rest: mods, version and connection.

Where to start

Install and update

From download to first launch, and how the app keeps itself up to date.

Requirements

• Windows 10 or 11, 64-bit.
• An internet connection (to download the server and Java, and to connect with your friends).
• Enough RAM for the server: the app accepts a minimum of 2 GB for the server, but 3 GB or more is recommended, always leaving at least 2 GB free for Windows.
• To play, you also need Minecraft Java Edition installed.

Installing

1. Go to the download page and click Download for Windows.
2. Open the downloaded .exe installer. There is nothing to configure during installation.
3. When it finishes, open Cubicase.

First launch

The first time, the app shows a welcome screen asking what you want to do: Host a server (create and manage your server) or Connect to a server (join a friend's server with a code). This only decides which tab opens first, and you can change it later in Settings → Home.

Updates

Cubicase checks for new versions on its own. When there is one, a "New version available" notice appears with the Update and restart button. The app downloads the update, shows the progress and restarts. If it fails, it tells you and you can try again later. The installed version number appears at the bottom of Settings.

The notice can be dismissed, but the Update button stays in the top bar while a new version exists. If the installation fails, it changes to Try again: the app checks again for an update and tries to install it, with no need to close and reopen the program. After a failure, it stays disabled for a few seconds so it doesn't overload the server, and repeated clicks are ignored.

Getting to know the interface

A quick map of everything you see in the Cubicase window.

Top bar and general shortcuts

• Host and Guest tabs: switch between managing your own server and using the library of your friends' servers.
• Settings: general app preferences: startup tab, backups, theme, language, account and subscription. See App settings.
• Theme switch: quickly toggles between light and dark mode (also in Settings).
• Update button: only appears when there is a new version. If the automatic update fails, it becomes Try again and you can try once more without closing the app.
• ? button (Help center): opens shortcuts to this tutorial and the form to report bugs, problems or suggestions. See Help center and contact.
• Diagnostics center: the history of warnings and errors (network, server, installation…). See Diagnostics.

Host tab

• Local Servers list (sidebar): all the servers you created or imported. It holds the buttons to create a server, import a server and import a modpack.
• Selected server panel: name, status (Online, Starting, Stopping, Crash, Offline), invite code, start/stop buttons and RAM/CPU usage.
• Invite your friends: the code to share and the connection status (technical details are collapsed).
• Console: two tabs, Minecraft Console and Connection, with live logs.
• Management: players, mods/plugins, world and backups.

Guest tab

The Library of Known Servers: every server you have joined stays saved, with its status, players and the play button.

When you close the window

Cubicase asks what to do: Keep running in the background (server and network keep running) or Close everything (stops the server, the network and the app). See Background and closing the app.

Create a server

From clicking the "+" to an installed server, step by step.

1. In the Host tab, in the Local Servers list, click the + button and choose Create New Server.
2. Fill in the Server Name (e.g. My_Server). See the naming rules below.
3. Choose the Server Type. If you're unsure, see Which type to choose.
4. Choose the Minecraft Version. The selector has a search box and groups versions into Recommended, Popular and All Versions.
5. If the type is Forge, Fabric or Paper, one more selector appears (Forge version, Fabric Loader version or Paper build). The app already selects the recommended/stable option.
6. Adjust the Allocated RAM (see below).
7. Optionally, enter a World Seed.
8. Click Create Server and wait for the installation.

Naming rules

• It can't be empty or repeat the name of another server of yours.
• It can't contain the characters \ / : * ? " < > |.
• It can't end with a space or a period.
• It can't be a reserved Windows name (such as CON, NUL, COM1).

Minecraft version

Cubicase offers versions starting at 1.8.9. When in doubt, stick to the Recommended ones. If your friends use a specific version (or a modpack requires one), pick exactly that: everyone must play on the same version as the server.

Allocated RAM

This is the memory the server may use. The app shows your PC's total and warns you:

• Less than 3 GB: can cause slowdowns or freezes, especially with many players or mods.
• Leaving less than 2 GB for Windows: can make the system slow or unstable, so lower it.

Rule of thumb: a vanilla server with a few friends runs fine on 3-4 GB; heavy modpacks need 6-8 GB or more, if your PC allows. You can change it later in Server Settings.

World seed

Leave it blank for a random world. If you want a specific world, type the seed. You can only set it now: the world is generated the first time the server starts, and the seed can't be changed afterwards. To generate another world later, use Reset World (see World and backups).

What happens during installation

• The official server files are downloaded (Mojang, Forge, Fabric or Paper depending on the type). This happens once per installed version.
• The required Java is downloaded automatically when missing (see Automatic Java).
• Cubicase accepts the Minecraft EULA and creates the initial server.properties for you.

Which server type to choose

Vanilla, Forge, NeoForge, Fabric or Paper: what each one does and when to use it.

Mods versus plugins

• Mods (Forge, NeoForge, Fabric) change the game from the inside. In general players also need to install the same mods. Cubicase does this for the guest, see Prepare and play.
• Plugins (Paper) run on the server only, and players join with plain Minecraft.
• Mods and plugins are not interchangeable. Each loader requires files made for it and for the chosen Minecraft version.

Start and stop the server

How to turn the server and the network on, what each status means, and how to shut down safely.

Turning on

1. Select the server in the Local Servers list. Only one server can run at a time: stop the current one before switching.
2. Click Start Server. The button shows Starting… while Minecraft boots, and Cubicase connects your friends automatically — there is nothing else to turn on.
3. When everything is ready, the status changes to Online for friends and the invite code is live to share. If you are connected as a guest on another server, you have to leave it first: Cubicase asks and disconnects for you.

The first time

The first start can take a while: the app downloads Java (if missing), and Minecraft generates the world. The progress bar shows how it's going and the console shows everything that happens.

The statuses

Turning off

• Click Stop Server and wait until it reaches Offline. Cubicase sends the stop command to Minecraft so everything is saved properly.
• Stopping the server also ends the connection with your friends, in this order: Minecraft saves the world first, then the connection is turned off.
• From the console you can also use stop.

Automatic Java

You don't need to install Java. Cubicase picks and downloads (from Adoptium) the version your Minecraft version requires and keeps it in the app's data folder:

If a server's Java is corrupted or incompatible, Cubicase detects it, reinstalls it automatically and tries to start again, notifying you with "Fixing automatically".

Invite friends (code and link)

Three ways to hand your server to others: code, link and address.

Server code

Every server has a code in the format CF-XXXX. To copy it, use Copy Server Code (or Copy Code) in the server panel. The guest only needs it once, because afterwards the server stays saved in their library.

Invite link

The Copy invite link button copies an address in the format play.cubicase.net/…. When the link is opened, the guest's Cubicase opens and adds the server to the library. This works through the cubicase://join/… protocol, so the guest needs Cubicase installed.

The free link is based on the code. With Cubicase Plus you can choose a custom address (e.g. play.cubicase.net/my-server) in Server Settings.

Minecraft address

In Server Settings → Minecraft address is the address the player uses in the Multiplayer list. The free address is based on the code and only works while the guest is connected through the app. With Plus you can choose your own name.

Generating a new code

Next to the code there is the Generate new code option. Use it when the code leaked or someone you no longer want there has it.

• The old code stops working immediately: anyone who only had it can no longer join.
• You need to give the new code to the people who already play with you.
• You can only generate a new code with the server stopped.

Server console

Follow what Minecraft and the network are doing, and send commands.

The two tabs

• Minecraft Console: all of the server's output (players joining, warnings, errors). It only shows something after you start the server.
• Connection: logs of the connection with your friends. Useful for diagnosing when nobody can connect.

The Clear button wipes what's on screen (it doesn't delete the server's log files).

Sending commands

The text box at the bottom of the console only accepts commands when the server is Online. Type without the slash and press Enter. Some useful commands:

Many of these commands require your server's version and type to support them. Servers with plugins (Paper) and mods may have extra commands.

Players: whitelist, operators and bans

The Players panel controls who can join and who is in charge of the server, without typing commands.

With the server online, the actions in this panel are sent as commands through the console and take effect immediately. The panel has four tabs:

Online

Shows who is connected right now. With the server off, it says "Server offline — no players connected".

Whitelist (approved list)

While the whitelist is disabled, anyone with the code can join. A notice in the panel reminds you, with the Enable whitelist button.

1. Click Enable whitelist.
2. In the Whitelist tab, type the Player name (exactly the Minecraft nickname) and click Add.
3. To remove someone, use Remove from whitelist and confirm.

You can also turn the whitelist on/off in Server Settings → Whitelist.

Operators

Operators (ops) have administrator permission inside the game: they can use commands such as gamemode and ban. Add with Make Operator; the list shows each one's UUID and level. Remove with Remove operator.

Banned

• Ban: type the name and, if you like, a Reason (optional).
• Ban IP: blocks an entire IP address.
• The list has two sections, Banned players and Banned IPs. Use Unban or Remove ban to reverse it.

The Refresh lists button reloads everything in case something changed through a console command.

Mods and plugins

Install, disable and remove mods (Forge, NeoForge, Fabric) or plugins (Paper) without leaving the app.

On servers with a mod loader the panel is called Mods and uses the mods folder. On Paper servers it is called Plugins and uses the plugins folder. Vanilla servers use neither.

Search and install online

When you create a server with mods or plugins, this window opens by itself: it is the ideal moment to install world-generation or terrain mods, which must be on the server before its first start. You can close it and come back later.

1. Click Browse Mods Online (or Browse Plugins Online). The search combines Modrinth and CurseForge in a single list: each item shows which of the two it is on.
2. The window opens with the most popular items already listed. Use Category and Sort to explore, or type a name (e.g. Sodium, WorldEdit). Only what is compatible with this server shows up.
3. To install right away, click Install on the row itself: the app picks the latest compatible version and also installs the required dependencies. The window stays open, so you can install several in a row.
4. To choose the version or review dependencies first, open the item. Under Dependencies not detected there are checkboxes to install them together; if you already installed them manually, just uncheck them.
5. Restart the server: changes to mods and plugins only apply after that.

Ready-made modpacks

On the Modpacks tab of the same window you install a whole modpack onto the server you already have. The list only shows the ones compatible with the server's Minecraft version and loader. Before touching anything, the app downloads everything and shows a summary: how many mods are new, how many are already present and how many exist in another version.

• Keep the server's versions (recommended): what already works is left untouched.
• Use the pack's versions: the old files go to the mods-backup folder, they are not deleted.

Mods repeated between two modpacks are not duplicated, even if the file name differs: the app identifies each mod by the id it declares inside. The pack's configuration files never overwrite yours. Combining modpacks doesn't guarantee they work together.

Managing what's already installed

• Search: the field above the list filters as you type, by file name or mod id. Select all and bulk delete only apply to what the search is showing.
• Duplicate: a badge warns when the same mod shows up in two active files (different versions, for example), which can stop the server from starting. Remove one of them.
• Disable / Enable: turns a mod off without deleting it (good for testing which mod causes trouble).
• Delete: removes the file, with confirmation. You can select several (Select all) and use Delete selected mods.
• Open Mods Folder: opens the folder in Explorer, so you can copy .jar files downloaded from other sites.
• Refresh list: rereads the folder.

Pending mods

If a modpack has mods that couldn't be downloaded from any source, the panel shows a notice "N mods must be downloaded manually", with each mod's name, the modpack it came from and an Open page button. Download the file and put it in the mods folder: once the app finds it, the mod leaves the list by itself. When you start the server with pending items, the app asks whether you want to go ahead.

Manual installation

Copy the .jar file into the panel's folder and click Refresh list. Make sure the mod is for the same Minecraft version and the same loader as the server.

World and backups

Protect your world's progress: manual and automatic backups, restoring and starting over.

Manual backup

1. Stop the server. The app only manages backups while it is off, so it doesn't copy the world in the middle of a write.
2. In the World tab, click Back Up Now.
3. The backup appears in the Backups list.

Automatic backups

Configured in Settings → Backups (see App settings). When enabled, Cubicase creates a backup on its own:

• when the server is stopped;
• when the server crashes;
• periodically in long sessions (interval in hours, configurable).

It skips itself if the world hasn't changed since the last one. You set how many backups to keep (Keep the last N backups): older ones, automatic or manual, are deleted.

Restoring a backup

1. Stop the server.
2. In the backup list, click Restore backup on the one you want.
3. Confirm by typing RESTORE.

Resetting the world

Reset World permanently deletes the current world; Minecraft generates a new one the next time the server starts. Confirmation requires typing RESET. Make a backup first if there is any chance you'll want the old world back.

Where backups are kept

They live in a CubicaseBackups folder, separated by server name. If you rename the server, Cubicase moves the backups along; if it can't, it tells you where they stayed so you can move them manually.

Server Settings

A form for all the server.properties options and more, with no file editing.

Open it with the Server Settings button in the server panel. Two important rules:

• Options can only be changed with the server stopped. While it is running, the app says "Server running".
• If the app can't read the real settings, it locks the form instead of risking overwriting everything with wrong values. Close it and try again.

Identity

Game rules

Security and account

Performance and network

Click Save to apply. Changes take effect the next time the server starts.

Import an existing server

Already have a Minecraft server in a folder? Bring it into Cubicase without copying or losing anything.

1. In the Local Servers list, click + and choose Import Existing Server.
2. Select the folder where the server is (the one that contains the server.jar or equivalent).
3. Cubicase analyzes the folder and detects the type and version. Then the server appears in the list and the log confirms the import.

What changes for imported servers

• Files stay in the original folder. Cubicase just starts managing them there.
• You can't rename the server through Cubicase, since the name comes from the folder.
• If the Minecraft version isn't detected, the online mod search is unavailable and the version shows as "Not found".
• A server that is already in the list can't be imported again ("Server already imported").

Removing from the list

When you delete an imported server, Cubicase only removes it from the list. The original files in the folder are not deleted. For servers created by Cubicase, deletion wipes everything (see Delete a server).

Import a modpack

Create a modded server from a modpack file, with the loader, version and mods set up automatically.

Cubicase accepts two formats: .zip (CurseForge) and .mrpack (Modrinth).

1. Download the modpack file from the CurseForge or Modrinth website.
2. In the Local Servers list, click + and choose Import Modpack (.zip/.mrpack).
3. Click Click to select the file and choose the modpack.
4. The app reads the pack and shows a summary: Minecraft version, loader and number of mods.
5. Enter the Server Name and the Allocated RAM (big modpacks need a lot) and click Import Modpack.
6. Wait: Cubicase installs the mod loader and downloads all the mods. The bar shows the percentage and large modpacks can take a few minutes.

Already have a server and want to add a modpack to it? Use the Modpacks tab in Mods and plugins.

Once imported, your friends join as usual. Their Prepare and Play installs the same mods on each person's machine (see Prepare and play).

Delete a server

How to delete a server and exactly what is lost.

1. Stop the server. A running server can't be deleted.
2. In the Local Servers list, use Delete Server on the server you want.
3. To confirm, type the server name and click Delete Permanently.

For imported servers, only the list entry is removed.

Join a friend's server

You received a code or a link. Here is how to turn that into gameplay.

Option 1: code

1. Install Cubicase and open the Guest tab.
2. Click Add Server (or Add First Server, if the library is empty).
3. Paste the Invite Code (something like CF-XXXX) and click Add.
4. The server enters your library. Now go on to Prepare and play.

Option 2: invite link

If the host sent a play.cubicase.net/… link, just open it: Cubicase opens and shows "Server added". If the link is invalid or has expired, the app tells you to check with the host.

The library

You only need the code once: afterwards the server stays saved in Known Servers. Each card shows name, version, status, players (e.g. 3/8) and there are shortcuts for:

• Copy server code and Copy address;
• Refresh status, to query again who is online;
• Remove from library, which only takes it off your list and doesn't affect the server.

If one of the servers is yours, it appears marked Mine.

Common error messages

Prepare and play

The button that installs everything the server requires and opens Minecraft already connected.

Server without mods

Click Play. Cubicase opens Minecraft set up to connect to that server.

Server with mods

Here Prepare and Play appears. When you click it, a Prepare <server> window checks what you already have and shows what it is going to do:

• Install the loader (Forge, NeoForge or Fabric) in the right version in your Minecraft, if it isn't there yet.
• Select the right profile in the Minecraft Launcher.
• Download the missing mods, straight from Modrinth, copy them from the server folder (if the server is on your computer) or download them from the host itself when they don't exist in a public catalog.
• Isolate everything in a folder of its own for this server, without affecting your regular Minecraft or other servers.

Click Prepare now and follow each mod: ok, Modrinth…, copying…, host… or failed.

When it finishes

• All good: "Ready to play!". Click Open Minecraft.
• Some failed: the window lists which ones. Use Try again. If that doesn't fix it, you can Continue anyway, but the server may reject the connection or the game may crash because of the missing mod.

Manual connection and tunnel

How the connection works under the hood, and how to connect the "classic" way through the Multiplayer list.

Connect / Disconnect

When you click Connect on the server card, Cubicase establishes a tunnel through the private network to the host. When it finishes, the card shows Connected and the message "Connect to <address> in your Minecraft".

• The app tries to automatically add the server to your Minecraft Multiplayer list.
• If it can't find your installation or fails, copy the address with Copy address and add it yourself: in Minecraft, Multiplayer → Add Server, and paste the address.
• When you're done playing, click Disconnect to end the tunnel.

One tunnel at a time

One Cubicase installation uses the private network either as a host or as a guest at a time. If you're connected as a guest, the host's network button is locked ("In use by Guest mode"), and vice versa. Stop one before using the other.

Local guest port

In System Settings there is the Local Guest Port (default 25565): the local port used only when you join someone else's server. It doesn't affect the servers you host, whose port is set in Server Settings. Only change it if another program is already using 25565.

Status and “Wake server”

What each label on the server card is telling you.

Wake server

When the host uses the on-demand server, the server stays in Standby until someone needs it. Click Wake server: the app shows "Waking up, please wait…" and turns the server on. If you ask again too quickly, it tells you to wait a few seconds. If the server takes too long, try again.

Without internet

Without a connection to the central system, a notice appears in the library: the information shown is from the last saved snapshot and may be out of date.

App settings

The Settings button gathers Cubicase's general preferences, in sections.

Home

Tab on startup: choose between Host (host a server) and Guest (connect to a server). It is the screen that appears when Cubicase starts.

Backups

• Automatic world backup: turns automatic creation on/off (on stop, on crash and periodically).
• Keep the last N backups: how many to keep. Older ones, automatic or manual, are deleted.
• Safety backup interval (hours): in long sessions that are never stopped, creates an extra backup every so many hours.

Details on restoring in World and backups.

Theme and language

• Light / dark mode: also reachable from the switch in the top bar.
• Language: the app interface language. In Automatic it follows the Windows language.

Account and Subscription

See Account and sign-in and Cubicase Plus.

Account and sign-in

An account is optional. It is used for Cubicase Plus and to link servers to a profile.

Signing in

1. Open Settings → Account and click Sign in.
2. The browser opens the Cubicase sign-in page. You can sign in with Google, Discord or a magic link (a link sent to your email).
3. Once signed in, the browser hands you back to the app, which then shows "Signed in as <your email>" and the linked providers.

Setting a password (optional)

Under Set password you can create a password to sign in without depending on the magic link/Google/Discord. Minimum of 6 characters.

Signing out

Sign out disconnects this computer. Your servers keep working normally.

Cubicase Plus

Cubicase is free. Plus is an optional subscription that unlocks extra features.

What Plus unlocks

• On-demand server: the server starts on its own when someone tries to join and shuts down on its own after a while with no players.
• Custom invite link: play.cubicase.net/your-name.
• Custom Minecraft address: an easy-to-remember name instead of the code-based one.

Subscribing

1. Sign in to your account (see Account and sign-in).
2. In Settings → Subscription, choose the Monthly or Annual plan.
3. Complete the payment on the secure page that opens in the browser.

After subscribing, the active plan appears with the renewal (or cancellation) date. Manage subscription opens the portal to switch plans, update payment or cancel.

Setting up the on-demand server

1. Select a server in the Host tab (a server must be selected).
2. In Settings → Subscription → On-demand server, turn the option on.
3. Set Shut down with no players after how many minutes.

With the mode on, the server panel shows the notice “Shutting down for inactivity in N s” shortly before shutting down, with the Keep running button to cancel.

I stopped the server and it no longer wakes up

That is on purpose. When you click Stop Server with the on-demand mode on, standby is paused: the card shows Standby paused and a notice, and your friends can't wake the server (so nobody turns it on in the middle of a mod change or a backup). To turn it back on, click Back to standby in the notice, or Start Server. Shutting down for inactivity, or a stop typed in the console, does not pause it: the server goes back to standby on its own. If you close and reopen Cubicase, standby also goes back to normal.

Web panel

Monitor and control your servers from the browser, from anywhere.

The panel is at cubicase.net/painel. You sign in with the same account used in the app (Google, Discord or magic link).

What you can do

• See the servers linked to your account and the state of each one (online/offline).
• Start and stop servers remotely. Cubicase must be open on the host's computer: the panel sends the request and the app carries it out.
• Follow the console and send commands, when you have permission to.
• Share access: give other people permissions over the server (for example, view only or also control), without handing over your account.

If the panel asks to start a server while another one is already running, the app refuses and tells you ("Remote start refused"), because only one server runs at a time.

Background and closing the app

Closing the window doesn't have to take the server down.

When you close the window with the server or the network active, Cubicase asks:

The app stays active in the system tray (near the clock). To bring the window back, click its icon.

Diagnostics and automatic alerts

Cubicase watches the server and your PC and warns you before a problem ruins the session.

Diagnostics Center

Every important warning goes into the Diagnostics Center history, classified by source (Network, Server, Panel, Invite, Installation, Backup) and level (Info, Warning, Error, Critical). Use Dismiss to close a warning and Clear history to empty the list.

Lag detection

Resource analysis

When there is lag, the app checks whether the bottleneck is the processor or the memory of the PC, and tells you which:

• CPU at its limit: lower the View Distance, remove heavy mods or (long term) upgrade the processor.
• RAM almost full: lower the RAM allocated to the server, close other programs or add RAM to the PC.
• Neither at the limit: the likely cause is a specific mod/plugin or too many entities/players loaded.

There are also sustained pressure warnings: the computer's CPU or RAM above normal for a few minutes, even before lag shows up. A computer RAM/CPU usage bar (not just the server's) is always visible in the panel.

Out of memory (OutOfMemory)

If the server runs out of RAM, the app compares what you allocated with the PC's total:

• If the PC has headroom, it suggests a safe value to raise in Server Settings.
• If the PC is already at its limit, it suggests reducing mods/players, lowering the allocated RAM a bit or upgrading the RAM.

Common errors and crashes

When the server closes on its own, Cubicase reads the log and explains the most likely cause in plain language.

A red notice appears in the panel with the title and explanation. Click Show technical details for the raw log excerpt (useful when asking for help). If Automatic backup is on, a backup is also made on the crash. Causes the app recognizes:

A general method to find the culprit

1. Read Cubicase's notice and the technical details.
2. Remember what changed: did you install a mod? change a setting? raise the view distance?
3. Undo the last change (disable the mod, restore the setting).
4. If the world may be damaged, restore a backup.
5. If nothing works, ask for help with the log in hand, in Issues on GitHub.

Nobody can join

A checklist in the order problems show up most often.

On the host's side

1. Is the server Online? (If it's Starting, wait.)
2. Is the status Online for friends? If it shows Online on this PC only with a notice, click Try again (or Open to friends).
3. Is Cubicase open and the PC not asleep?
4. Did you not generate a new code recently? If you did, hand out the new code.
5. Are you currently using the app as a guest of another server? That occupies the network (see Manual connection and tunnel).
6. Look at the Connection tab of the console for errors.

On the guest's side

1. Is the code correct? "Server not found" points to a wrong or old code.
2. Is the status on the card Online? If it's Running on the host's PC only or Offline, the problem is on the host's side.
3. Did you use Prepare and Play (or Connect) and wait for "Connected"?
4. Do your version/mods match the server's? Run Prepare and Play again to reinstall what's missing.
5. Does the server use a whitelist? Ask the host to add your exact nickname.
6. Official Minecraft account: with Online Mode on (default), only people with an official account can join.
7. Try Disconnect and Connect again.

If the direct connection doesn't work: plan B with Radmin VPN

On some internet connections (certain providers, workplace or school networks) Cubicase can't link the computers directly. It's nobody's fault, and there's an easy way out: Radmin VPN, a free program that makes both computers see each other as if they were in the same house. You and your friend both need to install it (about 5 minutes).

1. You both download and install Radmin VPN (free, no account).
2. The host opens Radmin and goes to Network → Create network, picks a name and a password and sends them to the friend.
3. The friend goes to Network → Join network and types the name and password.
4. In Cubicase, open Help (?) → Can't connect?. The host's Radmin address shows up there, ready to copy; the host sends it to the friend.
5. In Minecraft, the friend goes to Multiplayer → Add Server, pastes the address and joins.

Your server and your world stay exactly the same. Only the way the connection travels changes.

Help center and contact

Found a bug, have a question or an idea? Talk directly to the people who make Cubicase, without leaving the program.

1. Click the ? button in the app's top bar.
2. Choose the Type: Bug, Problem or question, Suggestion or Something else.
3. Write the Subject (one sentence) and the Description: what happened, what you expected and, if you can, the steps to reproduce.
4. Enter Your email: that's where the reply goes. It stays saved on this computer for next time.
5. Leave the option to include the app and system version checked (it helps us fix things faster) and click Send message.

The same window has the Quick guides, shortcuts that open the most useful articles of this tutorial in your browser.

About privacy: we use your email only to reply to the message. Nothing beyond what you wrote and the app and system version (if you leave it checked) is sent.

Frequently asked questions

Is it free?

Yes. Cubicase is free and its source code is available on GitHub (FSL license). Cubicase Plus is an optional subscription with extra features.

Do I need to open ports on my router?

No. Cubicase connects directly, with no need to open ports and without exposing your router.

Do my friends need to install Cubicase?

To join with the code/link, yes: their Cubicase makes the connection (and installs the mods, if any). Only the host creates the server.

Does the server work with my PC turned off?

No. The server runs on your computer. If the PC or Cubicase is off, nobody can join. Plus's on-demand mode starts the server when someone arrives, but the computer must be on.

How many players can it handle?

It depends on your RAM, CPU and internet, and on the server type. Start with a few friends and watch the RAM/CPU usage in the panel. If there is lag, see Diagnostics.

Can I have several servers?

Yes, several in the list, but only one runs at a time.

Can I play on Bedrock, on a phone or on a console?

Cubicase is made for Minecraft Java Edition on Windows.

I changed PCs. How do I take my server with me?

Copy the server folder (or the backup) to the new computer and use Import Existing Server.

Where are the server files?

In Local settings → Server Directory the path is shown, with the Choose directory button.

How do I change the app language?

In Settings → Language.

I found a bug or have a suggestion

Use the ? button in the app (see Help center and contact). You can also open an issue on the project's GitHub, ideally with the text of the error's technical details.

Glossary

Terms that appear in the app and in this tutorial.