Problem Overview

One user reported: “I can’t create meetings in Teams. It says I don’t have permission.” Initial checks showed:

• Correct Microsoft 365 license assigned
• Teams working on both web and desktop
• No issues with Exchange or Outlook
• No Conditional Access or meeting policy blocking meetings

Despite all of the above, the error persisted — and soon other users reported the same issue.

Symptoms

• Users appearing as “Unknown” in the Teams calendar
• Calendar availability not visible
• Unable to schedule meetings from Teams

These symptoms indicate Teams couldn’t read calendar data for other users.

Root Cause

Check the Microsoft Online (MSOL) company setting that controls whether users can read other users’ calendars:

If the setting returns False, users can’t read each other’s calendars and Teams will fail to show availability or create meetings.

Fix — PowerShell Command

To enable calendar visibility across users, run the following PowerShell command as a Global Admin (or a role with required permissions):

Note: You must have the required permissions and the MSOnline module loaded to run Set-MsolCompanySettings. Consider running this in a maintenance window or test tenant first if you have strict change controls.

Results After Applying the Fix

• Users were able to create meetings in Teams again
• Calendar availability displayed normally
• The “Unknown” label next to people’s names disappeared

Additional Troubleshooting Tips

1. Ensure the MSOnline PowerShell module is installed and you’re connected to your tenant.
2. Confirm users have the correct Exchange Online mailbox and licenses.
3. Check for any Exchange sharing policies that might override tenant-level settings.
4. If the issue persists, review Teams and Exchange logs and open a Microsoft support ticket.