Linux Mint 20.3, TBird 91.9.1, FFox 101.0.1.
Regarding TBird & FFox:
New TBird email & new FFox history are saved to my profiles, but UI changes/settings are not.
Obviously, there's nothing wrong with the profiles or the permissions (and there has been nothing wrong with the profiles for 5 years).
The only common factor that I know of is Gecko -- implemented at v.68 to the best of knowledge.
I had to stop using FFox -- switched to Pale Moon -- several years ago. I stuck with TBird 52.7 for 5 years, but then (a week ago), along came mandatory Oauth2, I had to 'upgrade', and this problem appeared and must be dealt with.
My profiles are in VBox shared folders. I have NEVER had any troubles with VBox shared folders, whatsoever, that traced to Oracle code. The whole idea/claim that Oracle is to blame I find ridiculous. Virtual machines are their business and reliable shared folder architecture is at its core.
Can this 'now the profile is read/writable, now it isn't'-problem be solved? I'm available for/willing to do testing if someone can craft a suitable troubleshooting/tracing strategy.
Regards,
Mark Filipak.