Parallels Extensions do not Install/Uninstall (ARM,Win11,OSX Host)

After the most recent Parallels update, my ARM based Win11 image executed the Extensions upgrade. However, it failed, but then rebooted before I could capture the error message. From that moment the Extention is no longer working. there is no sign of it being installed (eg. in services, in programs, or anywhere else). The "Reinstall Extensions" link is there, and it does mount the CD.

Whenever I try and install the extensions, manually or otherwise, nothing happens, it's as if I never clicked it. I've tried as Administrator, and I've tried without. I've also followed the articles that describe how to manually uninstall the extensions and install, and in addition to those steps being very complex, it didn't sovle the problem.

Right now the application I'm running in Parallels is broken as it can't see the Shared Folders, and I'm keen to get this resolved.

 

What a terrible support experience. After not getting any response here I raised a ticket:
1) First ticket ignored everything I wrote describing the issue, and gave me basic links to KB articles.
2) Second response told me to send "Technical Data", when I already had with the original ticket.
3) Then they schedule a call, listened to me for 30 seconds and said "have you tried building a new VM". Which of course will "work" but doesn't remotely solve the issue, and means a lot of work to rebuild. They then disappeared for 10 mins to come back and say "sorry, build a new VM is the only solution".

Why I had to jump on a call for that I don't know, and how this can be considered a satisfactory answer I don't know.