Using Classic Outlook on Windows for personal email, calendar, and contact management
Dear Henryk EG
Good day! Thank you for posting to Microsoft Community. We are happy to help you!
Based on your description, I have a general understanding of your issue involving permissions about the global administrator account. So first of all, if you have other global administrators in your organization, please kindly ask them to try logging in to the administrator center to check whether they got the same error information.
Also, if other administrators still got the same error information or if there are no other global administrators in your organization, since your issue involves administrator authority, and our forum lacks knowledge and authority in this area, in order to better help you and not waste more of your time, please contact the team dedicated to handling administrator related issues for further assistance, please kindly refer to link as below:
Online support and Find Microsoft 365 for business support phone numbers by country or region
If your problem persists, so if you receive some error messages or error codes, then please kindly share the screenshot with me so that I can do further research and testing, thank you.
Thanks in advance for your understanding! Your patience and cooperation will be highly appreciated. Hope you all the best!
Sincerely,
Kerry Chen | Microsoft Community Moderator