The expire time bound publications task encountered a failure when waiting for aggregation requests to complete. It will ...

The expire time bound publications 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: Too many requests queued or server is under load.
Resolution:
Ensure that the server is functioning correctly and is not overloaded.