Teams stuck in a launch+crash loop

I am aware that this is an old thread, but looks like remains unanswered.

Although 5 years had gone past, I experienced much of the same issue, except there were no messages, which could be due to countless updates made since Sidney's problem. 

Teams would reboot 4 or 5 times after Windows start up (11 Pro), then shut itself down. When trying to launch it manually - same 4 or 5 reboots would ultimately bring it to a complete shut. 

I tried various approaches, from clearing cache files, reinstalling, cleaning the registry to closing all active sessions on other devices and browsers - with no luck.

Then one time , it worked no problem, then again and again, which got me thinking... what's changed in my setup/routine? It was the 2nd screen. When I boot up with 2 monitors on, Teams crashes almost every time, but when I boot up the PC on just a single screen and let Teams minimize to System Tray, it stabilizes without a problem and I can turn the 2nd screen on without issues. Now, if I try and turn the 2nd screen on with the main Teams window open - it will crash. Whether it's to do with drivers, or hardware - I don't know, but this walkaround works for me and I hope will help others.

Unfortunately, I couldn't post it on MS Learn, because the thread was closed unresolved.

This is what has worked for me:

• Uninstall Teams.

• Delete ALL folders under %localappdata%\Microsoft\Teams\, rather than just some of them, as indicated in most of the other solutions I found online.

• Also delete the HKEY_CURRENT_USER\Software\Microsoft\Office\Teams\PreventInstallationFromMsi registry value (always save a backup of the registry key before editing!!!).

• Reinstall Teams.

(https://answers.microsoft.com/en-us/msteams/forum/all/there-was-a-glitch-and-we-are-recovering/9ffa0f06-0c60-4d73-9ca2-7628f4543b11)

Hi Sidney,

I've also been expericeing the same issue over the last week or so on Windows 8.1 machines only.

Setting the "Teams.exe" in compatibility mode for "Windows 7" allows Teams to launch as normal but this is not an acceptable work around for us.

Would be good to find the root cause of this issue.

Sidney Andrews 

Hi Sidney Andrews ,

Have you tried clearing out AppData locations too, as I know sometimes an uninstall does not get rid of everything.

Might also be worth clearing out credentials too.

Thanks

Henry