Works for me. So lets try finding a why for why if does not work for you. So, there are really two very common causes of why email does not arrive after an update. THey probably account to well over 90% of those having issues. The first and by far the most common is your anti virus product is blocking access. Thins might revolve around "scanning secure connections" or it might be the firewall part of it blocking the new version number like a nervous child. Scared because it is unfamiliar. Either requires you to fix the anti virus settings so it gets out of the way. The second is changes to security requirement / Standards that occur from time to time. With Thunderbird 78 that was the cessation of support for TLS V1.1 and earlier. This will not be an issue for you as you are only talking about GMail and they support V1.2 and 1.3 (the last decades worth of undated changes) smaller providers and under resourced business mail servers appear to have been worst affected by that change So in the first instance I suggest you try the following to confirm there is an issue with third part software (most likely a security suite). Or you can start looking for setting in the security software to change. *Restart the operating system in '''[http://en.wikipedia.org/wiki/Safe_mode safe mode with Networking]'''. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: [https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode Windows 10], [http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode Windows 8], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-7 Windows 7], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-vista Windows Vista], [http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx?mfr=true" Windows XP], [http://support.apple.com/kb/ht1564 OSX] As an unrelated side, Gmail supports and prefers oAth as an authentication method for Thunderbird to get you mail. It removes the need to there to be a less secure apps setting and in the long term simplifies the authentication process as you are not fighting the direction Google are determined to go in. This authentication method does however require cookies to be enabled in Thunderbird. This is the default, but some security software routinely tun them off. "For your protection" .

Well done Matt! This found the problem Matt wrote this: "Restart the operating system in safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, OSX" I did the networking reboot and Thunderbird worked. So it was the antivirus, I have Nod32 and here is what helped me. - disable SSL filtering in the advanced ESET setup and click OK - re-enable SSL filtering and click OK - launch Thunderbird. And Tada all is well. Thanks again Matt!