• Start Windows in safe mode with networking enabled - https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode
• Still In Windows safe mode, start Thunderbird in Troubleshoot Mode - https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird

Does problem change? Pop accounts or imap accounts?

Please post to let us know

Thank you for your response.

After several hours updating drivers and bios, I am unable to open windows in safe mode WITH networking. It appears to be a known bug in W 11.

I have cleared TB start up cache 3 times now

I have 3 accounts, all are broken. Two gmail and one yahoo, all started on 29 Nov.

The accounts are imap; ssl/tls; OAuth Port is 993

SMTP is outgoing server

If I am unable to use safe mode with networking, is there another option?

I tried to uninstall/install, but it didn't remove data on the uninstall and the new install has the same issues.

> After several hours updating drivers and bios, I am unable to open windows in safe mode WITH networking. It appears to be a known bug in W 11.

Do you have a URL reference that describes why this would fail to start?

I'll go back and see if there are specifics, however, many reddit and MS post discuss this and how to fix it. None of the suggestion have worked. I've done msconfig, cmd line with bcdedit, shift restart and using the supplied options from MS.

I tried to uninstall TB and re install. Apparently uninstall does not remove from registry (or something) as the re install just loaded all the previous dl and still stuck on 29 Nov.

As far as the safemode with networking, it is known it doesn't work using wifi. I have an ethernet connection to a mesh satellite. As far as the computer is concerned, I'm on a wired connection. Wifi is turned off. All drivers have been updated per suggestions on MS site.

I'd like to try a complete uninstall/re-install.

I have a Realtek adapter. According to this thread, doesn't load drivers in safe mode.

https://www.elevenforum.com/t/reboot-safe-mode-with-networking.17048/

I am going to expand the scope. I have the same problem. I am using an iMac (Sequoia 15.1.1) and ThunderBird v 128.5.1esr (64-bit). I've been using TBird for years.

T-Bird gets messages from the server at OPEN but fails to get messages despite settings and manual "Get messages" since I upgraded (Sunday, 12/8). My current work around is to close TBird and re-open. Works, but a major nuisance.

So I did get the uninstall to work. Now, when I try to re-establish the service, using logins info that does work online to my email, I get this: "Unable to login at server. Probably wrong configuration, user name or password." I am using the setup provide in TB: ssl/tls and OAuth along with the default ports and my username and password.

This happens for yahoo and gmail, VPN off or on. Again, I've used TB for years and it's only since 29 Nov that I've had issues.

Yesterday, after updating every driver I could think of, uninstalling and reinstalling TB etc, and finally getting safemode to work, the app updated all of my email accounts.

Today, it won't download new emails OR send email.

So the behavior basically hasn't changed. I will try safemode again.

Anyone with a thought on solution?

I rebooted into safemode and the download and app works.

Troubleshooting recommends turning off add ons etc: I have none.

Troubleshooting recommends turning off hardware acceleration: I did this. Still worked in safemode BUT the app does not work in regular mode.

Thanks to all who read.

I DL TB for android in a sandbox on my computer (Bluestacks). It has the same issue. So what on my computer is interfering, that started suddenly on 29 Nov?

For anyone who might read:

Resolved this.

After years of running TBird and Norton together, apparently they are no longer compatible. I found another thread on the TBird/Mozilla site that discusses this: https://support.mozilla.org/en-US/questions/999433

I turned OFF the email functions in Norton 360 and I am now able to use TBird.

Thanks Wayne for your input.

I tried to uninstall/install, but it didn't remove data on the uninstall and the new install has the same issues.

I know you've sorted this but, for future reference... ...You can manually remove all the data files if you don't need the email texts and settings. After Uninstall and reboot, delete C:\Users\[User name]\AppData\Roaming\Thunderbird or move it to the Desktop just in case you need to put it back if you get an error message.