Issue
While decommissioning old Exchange 2007 server, Exchange uninstall failed with following error:
Object is read only because it was created by a future version of Exchange: 0.10. Current supported version is 0.1.
Trying to remove Public Folder Database via Exchange Management Console (EMC) also failed with the same error.
Solution
Resolved by removing the PF database via Exchange 2010 Management Shell (EMS):
Remove-PublicFolderDatabase -Identity "exch-2007\PF Storage Group\PF Database"
Exchange 2007
Exchange 2010
