Cause:
Collecting all root gameobjects with MeshFilters, but not checking if they actually have a mesh assigned. So allMeshesInScene contains null values
Fix
Check for null.
Related:
Destroys mesh but not gameobject. (should be marked DontSave but that's another known issue)
Are helper meshes not saved somewhere when they're generated?
This feature can probably double as a temporary fix for #386 and other DontSave objects being saved for some reason
Should probably set the toolbar back to "Show Only Visible" when destroying
At line 625.
Cause: Collecting all root gameobjects with MeshFilters, but not checking if they actually have a mesh assigned. So allMeshesInScene contains null values
Fix Check for null.
Related:
DontSavebut that's another known issue)DontSaveobjects being saved for some reason