I encountered the same exact problem today with Microsoft 365 Business Premium account on a Windows 11 Pro system -- could not active Office let alone get Outlook configured. The problem is specific to the Windows account.
Here are the steps I followed to troubleshoot and isolate the issue:
- Checked the default browser (Microsoft Edge)
- Ensured JavaScript was allowed and enabled without any restricted domains - no change
- Reset browser to defaults - no change
- Placed *.microsoft.com into Trusted Sites under IE Compatibility mode - no change
- Changed default browser to Chrome - no change
- Ensured JavaScript was allowed and enabled without any restrictions in Chrome - no change
- Reset customer password for Microsoft365 - no change
- Signed into the same computer with my administrative account and was successfully able to active Office 365
- Signed into the same computer with the customer's account and problem persisted (Office was not active under her account) - no change
- Assigned customer account local administrative privileges and signed back in again - no change
- Disabled MSSP application ringfencing - no change
- Removed and recreated local profile - no change**
- Restricted all GPOs (including redirections) on customer AD account - no change
- Performed GPUpdate on customer device - no change
- Cleared all policy settings from workstation - no change
- Examined customer AD account and saw it was configured for a roaming profile
- Removed roaming profile configuration for AD account
- Removed local profile on workstation
- Logged onto workstation again and profile was genuinely new -- no redirects or roaming profile configurations operational -- launched Microsoft Word and successfully receiving prompt to authenticate with Microsoft account to activate product
- Opened Outlook and successfully configured via AutoDiscover to Exchange Online
- Removed administrative access for customer account -- condition still resolved
- Re-enabled application ringfencing -- condition still resolved
- Logged off workstation, rebooted, and logged back in as customer -- condition still resolved
- Re-enabled appropriate GPOs -- condition still resolved
** If I had not been dealing with a ROAMING PROFILE combined with other group policies that redirected everything all over the place, I suspect this step would have resolved the problem.
Check your Group Policies for redirection (do not redirect appdata) and look at the account itself to see if it is configured as a roaming profile.
Good luck!