Premiere pro wont stop crashing (Premiere Pro V12.1)

I have been having the same issues on multiple setups - my home MacPro, my colleague's MacPro, and my office Dell Pc, all of which are running 12.1 (the fact that the SAME PROBLEM is occurring across different platforms AND different projects tells me this is either operator error or a software issue).  I've trashed the preferences, opened the sequence in a new project, opened the project in a new project, updated permissions, cleaned the cache, changed the render engine multiple times, uninstalled/reinstalled, reset workspaces, basically you name it - there is NO change.  This is incredibly frustrating.  There seems to be no real continuity in terms of what is causing it either, so I can't even determine if there is/are corrupt media file(s).  The crashes won't even generate an error log for me to try to pinpoint the issue.  After about 20 minutes of smooth sailing, the audio playback will lag for 2-3 seconds before actually playing, and even the most mundane edit (i.e. trim, lift etc) will cause it to pinwheel, resulting in a "serious error" occurring followed by an immediate shutdown.  Does anyone have any advice or a workaround that I haven't employed yet?

I'm also having the same issue. I also have the Vega 64 GPU but I have 32GB of RAM. Also, do you have slow playback with audio files when scrubbing or playing through the source monitor? When trying to find a trim point for a song in the source monitor, it lags and makes it really hard to start and stop where needed.