In this file, or files derived from it, when I do Alt-B, everything is hidden from the viewport, not just things outside the box. In other files, alt-b works fine. Can anyone figure out what’s wrong with this file? I stripped it down to 460kb, and it’s just two static meshes now, and it still doesn’t work.
I have no idea what the actual problem is, but if you open the file and uncheck “Load UI”, the issue goes away. It would be interesting to know the actual cause… but hopefully the quick fix is sufficient.
P.S. You might need to close Blender and restart. Then open the file from File menu/F1, not the splash screen, in order to uncheck UI.