The No GC Logon task was unable to update all of the cached entries during its last attempt.
The group membership cache refresh task is behind schedule.
Consider forcing a group membership cache update.
If the number of entries is greater than 500, you should have also received a companion alert “Group Cache Refresh has reached the user limit for this domain controller.” In this case, follow the instructions for that alert.
Otherwise, the replication window is too short for the number of objects in the cache, and the only option is to extend the window.
For more information, see:
Microsoft Help and Support for Microsoft Windows Server 2008 and above
Microsoft Knowledge Base