I am so glad I make regular complete backups. Version 146 is a hot mess. Highlighted subject lines flashing, folders disappearing, On the second start of Thunderbird 146 I could no longer connect to hotmail, gmail, aol, juno, yahoo, All broke. Ended wiping 146 off the computer with REVO, deleting the profiles and reinstalling 145 and recovering the profiles and messages I used with 145 from backups made 2 days ago. Running the latest version of Windows 11. No need to reply, just a fair warning.