It seems to be a problem with the imported Render objects. It’s really strange since it worked perfectly about 2 hours ago. I didn’t get rid of any materials or meshes, so I have no idea why I would be getting these errors. The game plays perfectly well, the errors only occur in the editor. I even refreshed the browser a few times to see if that would fix it, but it didn’t unfortunately.
Yeah there’s nothing wrong with launching the game or editing stuff in the viewport, it’s only the thumbnails of the Render files. It’s not really disruptive (except for time as I can’t see what they look like), just very annoying, but I thought I might as well bring it to your attention in case it’s indicative of a larger problem.