This monitor detects if an event that is logged periodically is not detected. The default threshold is listed in the Configuration Section in this knowledge article.
This can be caused if there is problem logging events to the Windows Event Log or if there is a problem reading and collecting this event from the Event Log.
Check if there are any script errors in the Operations Manager event log for the LogEndToEndEvent.js script. This script logs the event that this monitor detects.
If there is no script error, check if there are any errors with the Windows Event Log Module having problems reading from the Operations Manager event log; this may be caused the action account not having enough permissions to either write or read from the event log.