patrickdrd

well I found out it's not about ccleaner (I wasn't using it to clean anything from tb anyway), there are problems with this update regarding imap folders as well: https://www.ghacks.net/2017/06/15/thunderbird-52-2-0-update-issues-with-imap-folders/ (same thing happened to me, I managed to fix it restoring my profile multiples times over the new one)

same problem here, work pc wasn't affected though, strange...