Hey all, I installed the current version of Tbird on a couple of machines for a friend, one machine worked fine for a month or so, then started giving the "unable to write the email to the mailbox, make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox" error. There is a ton of free space on his C: drive, hundreds of GB. Yesterday I installed Thunderbird to another of his PCs, also no 3rd party AV (both running Win 11), same exact error after downloading a handful of emails from a few weeks ago. To make things weirder he took his laptop (the machine that worked ok for a short time) to his office, where he has a different ISP and it downloaded all of his mail! What is going on here? I have seen plenty of threads about this error, I tried compacting, repairing the folder etc, nothing fixes the problem and Thunderbird sits there not syncing his mail. At the bottom of the window it shows that there are 200 or so emails to download, it looks like they are downloading for a bit, then it quits trying and gives the error. Is there a known cause of this seemingly common error? Are Thunderbird devs aware there's an issue that renders their software unuseable for some users? His mail account is with Brightspeed, an old centurytel.net account. Please share any tips you may have for overcoming this error, thanks!