An error occcurred on line 105 while executing script 'MOM Backward Compatibility Service State Monitoring Script"

We've been getting the following error for some time now.

An error occurred on line 105 while executing script 'MOM Backward Compatibility Service State Monitoring Script'

Source: Microsoft VBScript runtime error

Description: The remote server machine does not exist or is unavailable: 'GetObject'

One or more workflows were affected by this.

Workflow name: System.Mom.BackwardCompatibility.ServiceStateMonitoring

Instance name: server.domain.local

Instance ID: {INSTANCE}

Management group: GROUP

Unfortunately the instance in question has since been decommissioned and simply does not exist any more. 

We're currently on a repeat count of over 350,000 and I would REALLY like to get it stopped. I've had a look at adding an override but that points to the management server rather than the instance itself.

Does anyone have any suggestions?

thanks in advance!