Unable to Login to Teams on a Mac / Windows

Occasional Contributor

I have Teams installed on a Mac, a Windows 10 PC and my iPhone. It only works on the iPhone! On the Mac it says 'run into an issue' and 'try signing in again', which I have tried multiple times. I have re-installed teams, deleted everything Teams related from the keychain, looked in the library/application support/Microsoft folders for teams folders and the cache but found nothing. Even after all of that it still caches my last login name and then it fails when I try to log in. I think if I could clear it and start again it might work. As for the Windows PC it says ‘Someone has already set up Teams for your organization’ and it is a personal account. Re-installed multiple times there also. Any ideas?

9 Replies
What he opens in a browser? Doesn’t sound like a client issue but rather an account issue! Since it works an the mobile there’s something odd obviously. What does a edge or chrome browser say when logging in?

@adam deltinger  It comes back with the same message it does in the Windows app: ‘Someone has already set up Teams for your organization’ . Tried it in Edge and Chrome. Same with Chome on a Mac. I wonder if the account is seen as a business account rather than personal.

Are you using teams for life (personal use) or a teams free organization?

@adam deltinger 


Just personal.

I know that the web and desktop clients just started working for Teams personal in public preview. Make sure to have the latest clients.
Also do you get an option for accounts after login?


@adam deltinger 

No options... I have the latest installs. I have uninstalled and re-installed multiple times.

Hello @Peter992385 


If ever the problem persists, you can try this solution that I found on a blog :



I was having problems authenticating the Teams app on Mac Os with Catalina.


Thanks! @Alexversak65 


Your suggestion fixed the problem on the Mac. I had actually already tried most of the steps. The one I had not tried was restarting with the 'command-option-p-r' that does a reset to the Mac's NVRAM, PRAM, and SMC. That seemed to correct the issue.


Now all I need to do is get it working on Windows... I wonder if something is in the Registry - I will poke around and see if I can uninstall then delete any remaining registry keys and see what happens.


Thanks again


Uninstalling Team, removing Registry keys and two folders related to Teams (identified in the Registry) then re-installing after a computer restart seems to have resolved the Windows login problem as well.


Should not have to do this type of thing to get software working!