During my workflow I am joining meshes together and then using "Separate by Material" and vice-versa. During this process, sometimes the materials are not saved. I posted about it in this thread: Material names missing
- Open the Blender file
- Notice Mesh1 and Mesh2 have material slots and materials
- Join Mesh1 with Mesh2
- Go into edit mode, and select everything in the joined mesh and do "Separate by Material"
- Save the blender file
- Re-open the Blender file and notice the material slots are there, but the Materials are now "missing", as shown in the linked question
So why might this be happening?