This can happen when you right-click on an asset in the asset list and click on go to hierarchy, the tool will try its best to link assets and game objects, but sometimes it still fails. Your workaround there is to either search your game object directly in the hierarchy or reconstruct the game object by extracting the mesh, textures, etc.

This can happen when trying to preview / export meshes or characters, especially if you are on ZZZ, try the acl_fix branch. If it still doesn't work, there is not much you can do, sadly.

You tried to load your game directly, or too many assets at once 😉