QML Loader black screen WASM WebGL bug

Changing a QML Loader's source can cause the window to go black and report the following error in WASM builds:

WebGL: INVALID_OPERATION: drawElements: no buffer is bound to enabled attribute

Attached is a GIF demonstrating the issue in the particles3d example project along with an image of the console output from Chrome.

When you open some of the demos in the project and then click back the screen goes black but the application does not crash. It is still possible to interact with the scene and if you are able to re-click on another item in this example the issue can go away.

Also note that not all of the demos in the particles 3d project cause the problem. Only the following demos cause the issue:

• Snowing
• HeartTrail
• Qt Cube Burst
• Fire and Smoke
• Speedometer
• Sorting
• Model-Blend Particles
• Colorful Particles
• Attractor Shapes
• Fading In/Out
• Emit And Burst
• ParticleSystem
• Aligned Particles
• TrailEmitter Burst
• Animated Sprite

While the following do not:

• Giant Ocean Spider
• Emitter Shapes

"Model Shape" simply fails to load in my case with shader errors.

Note that I have also observed the same issue in one of my own projects mostly when loading 3D QML scenes but some normal 2D scenes as well. Unsure which version of Qt 6.2 the particles3d wasm example is using but in my case I was using 6.2.0 Beta3.