Dear Thunderbird Community, whenever I delete a message or sort a message into a folder the attached Error message appears. The result is very disturbing since no matter whether I click on OK nor the red button, my Thunderbird eMail account and all folders are empty - don't show any files anymore. I am forced to close Thunderbird and open it again each time !! The file I deleted is deleted and the file I transferred into the folder has been transferred but whenever I repeat any such activities Thuderbird basically shuts down showing attached Error message. I still have 350 Gigabyte free space on the disk and yes, of course, it's my laptop with me being the one and only authorised to write on it. Anybody with any idea what I could/should do to solve this issue? Best regards, Michael