> I have 20 accounts with mails

pop accounts? Who is the mail provider?

POP accounts from Simply.com (my own domains)

• 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 go away?

Yes, the freezing stops, when running Thunderbird in Troubleshoot mode.

These are the add-ons which are activated:

• Mail Merge
• Open Google Calendar
• Owl for Exchange

Language: English and Danish.

Today same problem even though in Troubleshoot mode. Loading endless.

> Yes, the freezing stops, when running Thunderbird in Troubleshoot mode.

I would then test to see which of the add-ons, or combination of addons, is causing the problem.

I am having the same issue running Thunderbird 128.6.0 on Win11.

I have tried excluding the profile folder on Windows Defender as suggested [https://support.mozilla.org/en-US/que.../1285317|here] but it didn't work. After the next restart, I can't even bring the Thunderbird window on top, it is completely frozen.

I have 1 Gmail account and 1 Hotmail account configured with no custom add-ons installed.

Now version 128.6.1esr

When I drag the Thunderbird window around, I then can see the mail I have selected. Maybe it have something to do with the graphic drivers (Nvidia)??