Opening older drawings in 2020 and BOM and annotations disappear when hitting save. I have to do an advanced rebuild to get them back. I am seeing this on more than one computer with similar hardware. Any ideas? and yes graphic card drivers are up to date. I think it only happens when older drawings are updated to 2020 not when creating new drawings.
Kelly-
See if it behaves running in the RX safe modes. You can bypass the settings and you might see a new dialog that was previously dismissed that would account for the behavior.
SOLIDWORKS Rx Safe Modes | GoEngineer
If these don't work then you might need to get your SOLIDWORKS VAR involved as there are some reported cases for 2020 reported to SolidWorks based on unique criteria.
I seem to remember a few other people seeing the same problem. I think it had something do to with fonts. Try changing them to a different one and see if that helps.