I had some strange problems with Thunderbird a week or so ago. Browsing the net I found Mozilla Support saying there was a problem with the latest update, and to go one version back. I did that and everything was fine. I started getting prompted to update again, but ignored it for a while to make sure I would get a working version. About fifteen minutes ago, I started getting prompted to re-enter my credentials for my primary account (a Gmail account). It was running slowly, but it accepted my credentials. Then I got a warning pop-up that Tbird couldn't connect to my secondary Gmail account. So I rebooted, tried again, same thing. Finally I decided to go ahead and update Thunderbird, but the behavior continues. I just now got a warning email from Gmail, for my secondary account, advising me that this is a "new" sign-in that it doesn't recognize. And I can see that I've got a new email in my primary's inbox when I look on my phone, but Thunderbird on my laptop is just sitting there, spinning its little circle and not showing the new email. I've had the same provider for years, same laptop for a year, nothing has changed. I've used Thunderbird for years with the same email accounts, everything normally works. I have Windows 10 and am now using 52.2.1. I'd really appreciate some help. Thanks.