Just thought I'd share this; I had SW2020 crash on me yesterday evening and it took my file with it. no bother i had backup enabled - except that was corrupted too.
I looked around and followed a few guides such as opening with e-drawings, Maintenance through Solidworks Rx and rebooting but no dice.
In desperation randomly tried SW in OpenGL (through SWRx) lo and behold it worked. I was then able to re-save the document with tessellation data(the original reason why e-drawings wouldn't touch it)
If you have a particularly bothersome file, try SW in OpenGL. it might just allow you to open and re-save.