Outlook Mac cannot connect to teams

Copper Contributor

I'm using Outlook for Mac 16.45 in German running on a M365-Account. Both Outlook and Teams are signed in with the same M365-Account that has correct licenses for these products.


Since some days, I cannot create a teams-link included calendar. It says I should login with my email address, that is already in use for the license. I get this error (see screenshot):


Authentifizierung erforderlich

"Outlook muss Ihre Kontoberechtigungen bestätigen, bevor eine Teams-Besprechung hinzugefügt werden kann. Melden Sie sich mit Ihrer E-Mail-Adresse * an."



Authentifizierung erforderlich

"Bei der Anmeldung bei Teams ist ein Problem aufgetreten. Versuchen Sie es später noch mal."


I tried following:

- Deinstallation of Outlook, sign-out, sign-in

- Deinstallation of Tems, sign-out, sign-in

- Logged out

- Checked Exchange account configured in Mac OS


all with no luck. What to do?



10 Replies

@silvan4 Finally someone else with the same problem. I am also waiting for a solution.

Hi Megabitbyte
I got a request to call IeveI 5 Microsoft Executive, but as a software company, I do think this should be solved via forum/tutorial.

@silvan4 Do you use Teams with more than one accaount/company? I can switch the company in the upper right corner and I don´t know if this relates to the problem.


Otherwise I have two email addresses in one exchange server. But I always use the same one for login.

@Megabitbyte I have one main account that is also the same with Exchange but also two guetst accounts. I can switch them in Teams, but I'm signed in with the main account. In Outlook, I cannot switch anything.

@silvan4 Same here. Maybe it´s a problem with more than one account in teams?

This may be, I was invited to these two groups a couple of days ago and I think it could very well started at this point. How can I get rid of these groups?

@silvan4 Login to https://myworkaccount.microsoft.com/organizations and there you can leave the organizations you want to.

Signed out from all other organizations. Didn't change a bit.
@Pernille-Eskebo: How to resolve?

@silvan4 I left the other organization (guest) and uninstalled teams and installed it again. But upper right I have still the other organization even I can´t switch, because I can´t log in there anymore.


I also deleted the folder Teams under /Users/<myUser>/Library/Application Support/Microsoft (after deleting the app).


@Megabitbyte I haven't done anything but today it works. Seems like this function calls a webservice that was not available. What about you?