Failed to connect to back-end database. Lync Server will continuously attempt to reconnect to the back-end. While this condition ...

Lync Server 2013

Failed to connect to back-end database.  Lync Server will continuously attempt to reconnect to the back-end.  While this condition persists, incoming messages will receive error responses.

Back-end Database: %1  Connection string of: 
%2
Cause: Possible issues with back-end database.
Resolution:
Ensure the back-end is functioning correctly.

Failed to configure the roll back bit on exchange due to malformed response from Exchange. You can run the roll back cmdlet ... Failed to configure the roll back bit on Exchange. You can run the roll back cmdlet again to configure the roll back bit ... Failed to configure the roll back bit on Exchange. You can run the roll back cmdlet again to configure the roll back bit ... Failed to configure the roll back bit on Exchange. You can run the roll back cmdlet again to configure the roll back bit ... Failed to connect to back-end database. Lync Server will continuously attempt to reconnect to the back-end. While this condition ... Failed to connect to back-end database. Microsoft Lync Server 2013, File Transfer Agent will continuously attempt to reconnect ... Failed to connect to back-end database. Microsoft Lync Server 2013, Master Replicator Agent will continuously attempt to ... Failed to connect to back-end database. Microsoft Lync Server 2013, Replica Replicator Agent will continuously attempt to ... Failed to connect to back-end dynamic database. Lync Server will continuously attempt to reconnect to the back-end. When ...