I recently installed thunderbird on a new computer, it was ok for some time, but after few days it stopped working. 1. No longer are any mails downloaded. But there is no error message, there is no visible problem, there is even no action showed in bottom left corner that there is even a thing happening. 2. Cannot send email with message that SMTP connection is not configured, but it is. It was working, nothing is changed, all the data in configuration are proper, but there is no message that it failed, it says that there is no configuration. 3. The default page on start of thunderbird cannot be loaded. I get an error with retry button. It looks like thunderbird wasn't trying to make any connection to remote. For my over 10 year's of using it i've never experienced such thing, can't find any similar error on forums.