Upgrade to last PD version rendered my MBP unusable

Did I miss something about the latest update?
I haven't upgraded to macOS Catalina because of the lack of backward compatibility, but I was expecting that this would not be an obstacle to upgrading to the last PD version. Maybe I missed a warning to this effect in the long list of changes posted on the information page?
In any case, after I left my MBP to perform the PD 15.x.x update (shutting down my Window 7 VM first), I found an unresponsive Mac on my return. Shutting it down with the power button, doing a disk repair and restarting seemed to restore the well-being of my Mac, but as soon as I tried to start my VM, the dreaded beachball reappeared.
I am currently repairing my external disk after I had to shutdown my Mac with the power button, and wonder what could be my next move once this is done? Do the same again (probably to the same effect)? Try a backup VM? Downgrade (if that is even possible)?
Thanks for any feedback.

 

Correction: my OS version is Mojave (10.14.6)

 

Windows XP, Windows 10 VM boot up fine.
Windows 7 "checking disks after improper shutdown..."

 

After an overnight "check", I found the task apparently completed, but as soon as I tried to go to the VM's drop down menu (I am using Coherence mode), the Mac froze. I had to hard stop it, reboot in safe mode, reboot in normal mode, only to discover that I could not copy my defective/corrupted(?) VM to a separate drive, as the copy failed with an error 100034 after 1 hr (200 GB VM...). Apparently I am not the first to have experienced that (Google "Repeated Corrupt Parallels .PVM file").
I am about to give up on that VM and revert to an old copy (which hopefully will work), but I just started a "Reclaim Disk Space" request, just in case...

 

Are you still at 15.0 or did you try the 15.1 update of PD posted yesterday? 15.1 helped me with a similar issue.

 

15.1.0, so that's not the problem.
Still reclaiming disk space, with a "30" that has appeared in the center of the flashing "rays" of the progress icon. I assume 30%, not 30 hrs (or days)?

 

7 hr for the reclaiming of a few GB, but I was finally able to copy the 192 GB vpm file to an external drive for backup.
Started the VM in safe mode, gave me some concern by being quite unresponsive, but eventually ran smoothly. Rebooted in standard mode, schedule a C: drive check, which just finished completing. Seems like the thing is back in order. I will update if anything else turns up.

Note: although it might have no bearing whatsoever on the outcome, I did allocate less resources to the VM during the process, and also turned on detailed logging. This might have been what slowed down the first reboot, so I turned that back off. Again, this is akin to voodoo to me, so do with this info what you say fit, and don't blame me if a second nose grows on your shoulder as a result.

 

OK, so the situation is not great after all.
The VM is apparently back but sluggish to the point of being useless. In fact I am staring at the wheel icon right now, trying to shutdown my VM and this has been going on for over 10 min.
One weird thing I noticed is that when I had managed to pull down the start menu in Coherence mode, it froze in place and when I was moving my mouse over it, the network activity of the VM would jump (both ways), and drop as I moved away:

 

I gave up on the VM and reverted to an older backup, which seems to be working just fine in PD 15.1.

 

It looks like the problem I encountered as triggered some soul searching at PD:

Parallels Desktop 15 for Mac 15.1.1 (47117)
This update for Parallels Desktop 15 for Mac 15.1.1 (47117) addresses overall stability and security issues, and includes the following fixes and improvements:

• Resolves an issue with a Windows virtual machine getting stuck while checking the disks after it was improperly shut down.

Needless to say, I am backing up my VM before upgrading.