My Thunderbird updated itself to 115.4.1 2 weeks ago. It was a total mess but I've managed to get it all working fine except I used to have An Inbox for all 5 email accounts which stood at the very top of the folder and accounts list. There is no such Inbox there now. I have 5 email accounts which, in the previous version before the update, all showed in the what you call Unified Inbox. When I go to View and then Folders and tick the Unified Folders it gets unchecked the moment I close the option down. I've looked at various solutions on this forum but cannot find anything that seems to work for me. I'm faily savvy with programing and computers but this one has me stumped. I've loved Thunderbird as I've had it some years but I want to get my love for it back :-)