Process %1 (PID=%2). Exchange Active Directory Provider lost contact with domain controller %3. Error was 4 (%6) (%5). Exchange ...

Process %1 (PID=%2).  Exchange Active Directory Provider lost contact with domain controller %3.  Error was 0x%4 (%6) (%5).  Exchange Active Directory Provider will attempt to reconnect with this domain controller when it is reachable.