Issue Definition:

Getting following error while trying to edit Windows Firewall with Advanced Security policy settings in the GPO on PDC.
Error: The process cannot access the file because it is being used by another process. Status: The rule was parsed successfully from the store.

Cause

Handles on group policy folder in SYSVOL by multiple client computers.

Resolution

Issue resolved after we disabled leasing on the PDC by using following registry:

Registry Key: HKLM\System\CurrentControlSet\Services\LanmanServer\Parameters
Registry Value: DisableLeasing
Default Value: 1

Rebooted the server.