GPO Management tab in GPMC returns error "Failed to compare two elements in the array"
A possible replication conflict has occurred, and a CNF object is created in the default naming context in Active Directory partition. This causes the object enumeration to fail and return an error.
If you open the GPOADmin console and select the live environment and the affected domain, you could also receive the following error message: "Enumeration Errors Guid should contain 32 digits with 4 dashes."
Please refer to the following KB article for additional information about this error message.
KB Article: Enumeration Errors Guid should contain 32 digits with 4 dashes
Once the enumeration error is resolved, it will resolve the issue on GPMC with the GPO Management tab.