Thunderbird 68.4.1 (64-bit) on Linux Mint 19.3 Cinnamon The folder structure under Archives (I have it set to do folders by year) vanishes after restarting Thunderbird, and none of the messages can be accessed (shown in ArchivesBlank.png, attached). The year folders do show up during the Thunderbird session in which they were first created, but I didn't get a screenshot to show this at the time. Now that the 2020 folder has been created, I have no email with which to trigger another folder to be created to take a screenshot of. Archiving 2020 messages now adds them to the existing 2020 file, but the Archives folder remains empty. Going to the Archives folder properties and clicking Repair Folder finishes instantly and has no discernible effect. Deleting Archives.msf and all the 20xx.msf files, and restarting Thunderbird has no effect. The msf files are regenerated, but all the 20xx.msf ones are 0 bytes and the Archives folder remains empty. In Safe Mode, the Archives folder is properly populated with the folder structure and my archived messages, regardless of if I deleted the msf files beforehand or not. As I view each year folder, the associated 20xx.msf file gets actual contents and is no longer 0 bytes. Going back and forth between Normal and Safe Mode, making no other changes, the messages are absent in Normal Mode and present in Safe Mode. The only extensions I have are the default ones that came with the install: Lightning, and FileLink for WeTransfer. I disabled them both, since I don't use them anyway, but that made no difference. Now that I look at the screenshots side by side, I notice that Local Folders also doesn't show up in Normal Mode. Perhaps that's related? Looking at the Local Folders settings in Safe Mode, I don't see any settings that would explain why it's not showing up in Normal Mode. I can't think of any global settings I might have changed to cause this either. The actual message archive files seem to be working properly. In Safe Mode, I can see that the emails are present. When I archive additional messages while in Normal Mode, although they vanish from my view in Thunderbird, they are being correctly added to the 2020 file, not overwriting it or anything. I can access them through Safe Mode if I really need to, so I'm not freaking out too badly. But something definitely seems to be wonky with Thunderbird's ability to display them to me.