The following error occurred in the EventLog:
An unhandled exception occurred and the process was terminated.
Application ID: /LM/W3SVC/1/ROOT/INSPIRE_AMD (or different WMS, CSW or WFS-G services name )
Process ID: 2296
Message: Insufficient resources to perform operation.
The LogPipe was configured (logging enabled in AdminConsole) for at least one service instance therefore it added log massages to the MSMQueue and eventually crashing the web services.
Disabling the LogPipe for the service instances resolved the issue.