JannisX11

I ran into the same issue. I thought it might have been related to multiple Windows accounts, but it seems more common.

I updated Minecraft Preview on my second Windows account first, and it ran fine after a restart. Then I tried to open it on my main account, and it updated fine and moved over all my worlds, but it keeps crashing on open just like in the video above.

We have discovered that the issue affects not only the opacity channel, but also the emissive channel.

The pixels in the attached image are marked with their respective value on the green channel. They have very low emissive values, but render with a high contrast. Which makes it difficult to produce smooth transitions between emissive and non emissive parts of a texture.

You called the field "creative_group" in the example files, when it should be just called "group". That's also what the Block Wizard exports.

I reckon this is intended since the items would be contained in the shulker box drop itself, which doesn't drop.