You can search in your save-folder whether you have files like this:
so they end with _autosave.blend. If the time/date + name fits, you can open them and if you are lucky, the autosave was at a time, when you work was pretty far.
2nd chance would be files which end with .blend1.
you can rename these files to .blend and then open them with Blender. This ...
In the case of Python API you can try 1 or 2 .for general case try only 1
Downgrade blender to blender==2.79 it would work
You can update your script according to blender version >2.79
You can try to clean the file you're working on, going in the outliner, changing it from "view layer" to "orphan data" and click the "purge" button many times, until only brushes remain, then generate.
Try also the advanced options, choosing to generate a new rig with a new rig name, instead of overwriting the previous rig.
There were multiple problems with the mesh, but it all came down to materials being assigned to the wrong places. The shirt material was assigned to the head, mouth, and eyes. Create new material slots for these areas, select the already working-on-other-character materials from the list of options for each slot rather than creating new ones, and assign them ...
Another issue I found is that you can not use any CAPS in your email. I generally capitalize my name in my email and it wouldn't take it.
When you use your email as a login, it should have automatically lower cased the email to check it but it doesn't.
"I can see your problem there., Are there any actual cuboids there that might be set to a volumetric material, and are appearing in the render?" - ZargulTheWizard
Yes, thats it! It seems my volumetric node for the fire wasnt set to an absolute black, making the actual cuboids themselves only semi-transparent.
I exported the file as an STL into Cura, and I saw your problem. The way I fixed it was by adding a solidify modifier to both of the meshes. You don't need to add a lot of thickness, but you do need some (I added 0.02 m).
Let me know if it works.