I am hoping someone can help me with the following please. One of the reasons I use Thunderbird (currently updated to 102.1.1 (32-bit) is because I have several email accounts and need to create several incoming filters to direct emails to various mail folders. This has worked fine since I set it all up in early 2019. However (yesterday?), one of my accounts has disappeared from the displayed folders list (left side of screen) for no apparent reason. That account still appears in the settings list and it also appears in the profile/mail folder, with contents, in Windows Explorer. I have tried deleting the folderTree.json file (& folderCache.json), with no effect. As an aside, in case it is relevant, two new folders have appeared in the displayed folders list. One is popstate-1.dat which has appeared as a sub folder in another account (below the inbox, sent, etc folders). The other is a totally blank folder (unnamed) at the same level as the main account folders. Any help in assisting me to get my lost account folder back will be very much appreciated!