I opened Thunderbird early this morning and all was well. I left for a couple of hours and when I came back to check my email, Thunderbird shows items in my inbox but when I click on one, an animated blue circle appears and the screen is blank. I cannot access any folder contents as the animated blue circle appears on each selection. I can access other email accounts that are not Gmail without issue. I opened my Gmail account in a browser and it is working normal. Is there possible some kind of sync issue going on? Is there any kind of troubleshooting process or a repair installation I can do without the possibility of losing any of my locally stored folders and settings?