No more mail account beta 101.0b1 (64-bits, win 10)

Hi there,
Since yesterday, following the update to version 101.0b1, Thunderbird asks me to recreate a new email account.
My profile is still there and the software is pointing to the location but the account problem is still there.
Before the update, everything was working fine.
Maybe a bug about the version ?

What mail account?

I did not experience any problem when testing the update from 100.0b4 with my Comcast POP3, or Google IMAP account.

All my accounts have disappeared from the interface.
When I opened thunderbird after the update, I had a tab for creating a new mail account.
In the left panel, no more mail is displayed although my profile is the right one and in the settings no more account exists.
I still have my address book working.