When Something Is Not Working
Most problems in Composer are one of a small number of things. Work down this page before assuming something is broken.
An edit seems to do nothing
This is almost always a form error somewhere else in the editor.
Composer will not assemble a configuration while any field is invalid. When that happens, the live preview stops updating, Save stops recording changes, and Publish stops working, all without an obvious message.
Look for the Fix in UI button, which shows a count of outstanding problems and takes you to them. The offending field is often in a section you are not currently looking at, which is why the cause is rarely where the symptom is.
Downloading while a form is invalid can also give you the last valid configuration rather than your current one, so fix the error before exporting anything you intend to keep.
A part will not hide or show
First, check in Play rather than in edit mode. Edit mode deliberately shows everything regardless of conditions, so you can work on parts that would normally be hidden. A part visible in the editor but correctly hidden in Play is working properly.
If it is wrong in Play too, the usual causes are these.
The parts are not separate in the 3D file. Use Parse Structure in the Models section and look at what is actually there. If the thing you want to hide is not listed as its own item, the model needs re-exporting.
The condition refers to a value that does not exist. Check the exact value on the option, not its label, since a rule matching Oak will not match an option whose value is oak.
Two rules both match, so one part appears on top of another. The Logic Overview shows every condition in one place, which makes overlaps visible.
The model does not appear at all
Check the file loaded without an error in the Models section, and check its size. Very large files take a while and can fail on slower connections.
If it loaded but you cannot see it, it may be far outside the camera's view or extremely small or large relative to the scene. Press Fit scene to model in the Scene section, which reframes everything around what is actually loaded. Note that it also replaces your camera, lights, skybox and background, so if those are already set the way you want them, move the camera by hand instead.
The model looks wrong
Wrong orientation, lying on its side or upside down, usually comes from how it was exported. You can correct it with rotation on the model, and it is better to fix it in the software that made it.
Materials looking flat or grey generally means lighting rather than materials. Check your skybox first, since reflective surfaces get most of their character from it, and check that you have a light with reasonable intensity. Fit scene to model rebuilds the lights and skybox for you, at the cost of discarding whatever is there now.
Everything is slow
Look at the file size first. This is the cause the overwhelming majority of the time, and What to Expect covers what a reasonable size is.
If you are using scripts, check how often they are triggered. A script recalculating on every keystroke will feel sluggish, and naming the specific controls that should trigger it fixes that.
The Models section shows a total size for everything loaded, with a warning when it gets heavy.
The 3D view gets stuck
Reset Scene rebuilds the preview from scratch. If the view has got into a strange state after a lot of editing, this clears it without losing your work.
Switching the rendering engine between WebGL and WebGPU also rebuilds the view. That is expected rather than a fault.
An option is missing on the storefront but fine in Composer
Check that you published rather than only saved, since those are different actions.
If you published, check the app embed is switched on and saved in your live theme, and that the product is linked to the project.
If a feature works in Composer but not on the storefront right after a plan upgrade, your storefront may not have been told about the new plan yet. There is a Sync storefront blocks button on the Subscription page for exactly this.
Still stuck
Send us the project file, which you get from Files, then Download project file. It contains everything we need to see what you are seeing, including your editor state.
[email protected], or our Discord if you would rather ask in the open.