Hello all, One of our users' Thunderbird installations was recently updated from version 102.2.2 to 115.0.1. At work, we use an offline network. We have no direct internet connection at all. We use a Microsoft Exchange mail server to handle inbound and outbound emails. When our user got a new computer last week and first signed in to Thunderbird, her folder structure was correct, but something went wrong because her inbox and sent folders were completely empty. She would get a notification whenever someone sent her an email, but when she clicked on it, it would just show her an empty Thunderbird inbox (she should have thousands of messages). I, and others, have verified her email server settings are correct and the same as on other systems not experiencing this issue. Her calendar events, contacts, and email certificates are all where they should be. It's just her messages that are missing. Now here's where it gets weirder. Having created a backup of her original Thunderbird profiles directory and profiles.ini file, I exited Thunderbird and removed those profile files/folder from her "C:\Users\<username>\AppData\Roaming\Thunderbird" directory. Upon restarting Thunderbird, it asked for her to log in. She used the address and username I verified were in the Exchange server, and upon signing in, her mail client synced all her messages correctly. However, as expected, her calendar and certificate info was still missing since those don't come from the Exchange server. So, when I close Thunderbird and put her original profiles back into the AppData\Roaming directory (adding, not replacing the new ones since that also doesn't work) and start Thunderbird, we're back at square one where she's got certificates, calendar events, and addresses, but no emails in the inbox or sent folders. Has anyone seen this before? P.S.: Sorry there are no photos. I can't post screenshots from any of our computers.