Although you can manage permissions in Exchange Management Shell, in ecp when you click on Manage Permissions on specific folder the following page is shown:
500 Unexpected Error
To resolve this issue:
1. Use PowerShell to check Public Folder Client Permissions:
PS > Get-PublicFolderClientPermission \FolderName |Format-List
2. Check if any user has a SID instead of a username
3. Remove users with SID if any:
PS > Remove-PublicFolderClientPermission -Identity \FolderName -User NT:S-1-1-11-11111111-1111111111111-1111
4. Check if you can manage Public Folder permissions via ecp
What if I’m not finding any rogue SID with the first power shell command?
Only thing I see that might be out of place is some user named Anonymous that shouldn’t be there that I can’t delete.
This solved the problem in my specific situation. If you have found another solution, I would appreciate if you would share it.
I ran Get-PublicFolderClientPermission \FolderName |Format-List and it returned it couldn’t find a process with the name \foldername – I hate powershell so very deeply.