The expire endpoints task encountered a failure when waiting for aggregation requests to complete. It will be retried, but ...

The expire endpoints task encountered a failure when waiting for aggregation requests to complete. It will be retried, but if this error continues to occur, the Lync Server service will need to be restarted.

Error code: %1
Cause: There are too many requests on the server causing an overload.
Resolution:
Ensure that the server is functioning correctly and is not overloaded.