Did you get it resolved. Running into the same thing. Restarted my Mac twice. The Parallels tools install blocks all access to the VM. I hate Parallels updates. They frequently lead to hours of headache. Next time I will listen to my inner voice and wait until I have a day to kill.
I have the same issue. I updated Parallels Tools and it just sticks at 100%. I've shut down the VM several times, have tried Stopping it, Restarting it, Rebooting, and it stays stuck.
I ended up resolving it by going back to a snapshot. I'm not going to update Parallels Tools again. This is the second time I've had issues with it.
