I encountered the “You have launched an older version of Thunderbird” warning dialogue (see image) the other day as I had occasion to revert to a system image from the day before (due to Windows Update crapping-out) and, in the intervening time, I had updated Thunderbird from 68.2.1 to 68.2.2. The quick solution (for me) was to exit Thunderbird Backup C:\Users\Bazza\AppData\Roaming\Thunderbird (which does not hold my actual profile, only the necessary basics such as profiles.ini and installs.ini [I also backed up my actual profile folder (located on D:\....) for safety] Restart Thunderbird Create a new profile via the afore-mentioned dialogue (in my case, to be safe, I used a guff email account) Update Thunderbird to 68.2.2 again Close Thunderbird Delete the new profile information just created at C:\Users\Bazza\AppData\Roaming\Thunderbird Reinstate the backup that I made above of C:\Users\Bazza\AppData\Roaming\Thunderbird For info, this was all on Win7(x86) machine The concern I have about this is that this warning dialogue was given when I had only moved from 68.2.1 to 68.2.2. Now, I may be wrong, but I rather suspect that profile changes (as referred to in the warning dialogue) are not that likely to happen for sub-sub-version increments (if at all?). After all, the message does state “Thunderbird may have made changes....” Given the above I can envisage quite a number of situations where unsophisticated users may roll back (probably most often using Windows System Restore – although, somewhat surprisingly, I see Win10 has System Restore disabled by default) and then get the warning dialogue and not know how to retrieve the situation (by either using something similar to my own method or by using Profile Manager). Whilst not a complete solution, might it be possible for Thunderbird to keep a track of when version updates actually deliver profile changes and thereby only issue the warning dialogue when really necessary?