Call2Teams - Customers
If you have received an admin invite and receive the above error the following should be checked.
Logout from all Microsoft accounts
Try accepting the invite in a private Browsing Session
Use Chrome or Edge
You may also find that you have had admin access granted for a different client/tenant account.
We have also noted that some email clients may modify the invite link. You can right-click and copy the full link and paste this direct into a private browsing session.
If none of the above help, please raise a ticket via the Help Widget.