Limits and Troubleshooting

Limits and troubleshooting

Limits

These are Minecraft's limits. Projects made for web and desktop can go further; see Advanced tools.

Thing	Limit
Screens per project	128 (web & desktop: 1000)
Controls per screen	512 (web & desktop: 16,000; Validate gives advice past 4,000)
Screen size sent to players	900 kB compressed (screens compress 20–70×, so even 500 controls fit easily). Validate reports a screen that is too big.
Screen size	16–4096 GUI pixels each way (web & desktop: 16384)
Sounds	.ogg in Minecraft; .mp3, .wav, .m4a also in web and desktop apps; 32 MiB each
Actions per event side	64
Particle effects	64 per project, 2000 particles alive per screen (50,000 where the browser has WebGL2) (web & desktop)
Tilemaps	512 columns, 512 rows and 65,536 cells each (web & desktop)
State graphs	64 per screen, 64 states each, 16 ways out of a state (web & desktop)
Fonts	.ttf, .otf, .woff2, .woff, 8 MiB each (web & desktop)
Script size	256 KiB each (web & desktop: 1 MiB; only attached scripts are exported)
Screen changes per script run	128 (web & desktop: 100,000). Every ctx.ui call and ctx.state.set counts; going over applies none of that run's changes. See [[Scripting limits
Time per script run	2 seconds
Saved games (ctx.save)	None in Minecraft (web & desktop: text only, 512 KB per game)
Label text	One line: longer text is cut to fit the label. Use several labels for a paragraph
Images	PNG, 8192 × 8192 px and 32 MiB each
Project / export size	256 MiB total, 2048 files
Download size (web & desktop)	Advice, never a refusal: the Export dialog and Validate warn past 100 MB for a web game and 500 MB for a desktop app. See [[How big should a game be?
Item List data	128 rows, 4096 characters of JSON
Row template	64 controls
Text input sent to the server	1024 characters
Panel / group nesting	32 levels
Undo history	200 steps
IDs	lowercase letters, numbers, _, starting with a letter, up to 64 characters

Troubleshooting

My anchors don't seem to do anything. Anchors keep a control's distance from an edge; they don't move it there. They act when the parent or screen changes size: resize the panel on the canvas, change the screen's Width, or use Apply size in Preview. In Minecraft they only apply when Responsive layout is on in Screen settings. See Anchors and responsive layouts.

A control is cut off or invisible. It's probably inside a panel and sticking out past the panel's edge (children are clipped), or its panel is hidden. Check Parent panel in Properties and the eye in Layers.

I can't click or drag a control on the canvas. It may be locked (lock icon in Layers; press Ctrl+L to unlock), or you're isolating a different group (press Escape). Select it in Layers instead.

Clicking selects a whole group when I want one control. Alt-click it, click its row in Layers, or double-click to isolate the group.

Align commands are greyed out. Hover for the reason. You probably need more independent objects, or to turn off Keep layer groups together. See Align and distribute.

The Delete key did nothing. The canvas needs focus: click the canvas first. Delete is ignored while you're typing in a field or while the Assets or Items list has focus.

The command button does nothing in Minecraft. Commands run with the player's own permissions. Test with cheats on or as an operator. Also check the handler's Permission level and cooldown in Events → Server.

/myproject.open says unknown command. Check the project Id in Project settings, that the JAR is in mods on both server and client, and that you restarted after adding it. Remove any older copy of the same project.

My screen changes don't show up in the game. JARs need a restart after being replaced. In the Minecraft test, use Apply changes and reopen the screen.

Preview says my server action ran, but nothing happened. Preview only simulates server actions. Use the Minecraft test.

The Minecraft test won't start. It needs Java 21: choose the folder in the test window. The first run downloads several GB and can take several minutes. With the portable ZIP, keep TestEnvironment beside Designer.

The export won't build. Click Validate and fix the errors listed in Output. Common causes: an action targeting a control that no longer exists, a missing destination screen, or an invalid ID.

Server scripts stop running for a player. They've used up the per-player script time budget; it refills within seconds, and the server log mentions throttling. Make scripts lighter, or raise the event's cooldown.

My AI assistant can't connect. The assistant must run on this computer and support MCP over HTTP. The port (4730) and token stay the same across restarts, so a configuration you copied once keeps working. Copy it again after Regenerate token, or if another program was using port 4730 (then a free port is used, and Copy connection config shows it). See AI assistants (MCP).

My script's variables reset on every event. Each event runs the script from the top unless the project keeps script state. In a web & desktop project, tick Scripts keep their variables between events in Project settings. Otherwise keep values in ctx.state. See Where to keep state.

A script says it asked for more than 100,000 (or 128) screen changes. One run made too many ctx.ui calls or ctx.state.set calls, so none of them were applied. Spread the work over several ticks, or let velocities, seek, paths and animations move things for you. 128 is Minecraft's limit and applies to projects made for Minecraft or both.

Resizing the window or turning the phone put my game back to the start. Games exported with earlier versions of Arcadia Studio put every control back where the editor had it when the window changed size. Export the game again: controls a script or the player moved now stay where they are.

The game forgets its progress when the page reloads. Save it with ctx.save; see Saved games. Screen variables and script variables last only while the game is open.

My second movement component stopped the first one working. Movement components used to share the screen's one tick event. They now each tick on their own control, and opening an older project moves them over.

I changed the project's ID and a script can't find a sound or picture. Changing the ID moves the project's files and updates every control and action, but scripts are text: one that names "old_id:..." must be changed to the new ID. Project settings lists them when you change the ID, and Validate points out each one.

The editor crashed. Reopen it and use File → Recover unsaved project…. A crash log is saved in %LOCALAPPDATA%\Arcadia Studio\Logs.

The panels are in a mess. View → Reset panel layout. It doesn't touch your project.

Where Arcadia Studio keeps things

What	Where
Recovery drafts	%LOCALAPPDATA%\Arcadia Studio\Recovery
Crash logs	%LOCALAPPDATA%\Arcadia Studio\Logs
Panel layout	%LOCALAPPDATA%\Arcadia Studio\workspace-layout-2.xml
Keyboard shortcuts	%LOCALAPPDATA%\Arcadia Studio\keybindings.json
Minecraft test instance	%LOCALAPPDATA%\Arcadia Studio\MinecraftTest\1.21.1
MCP exports	%LOCALAPPDATA%\Arcadia Studio\McpExports