A Wildcard matching rule fails and event ID 10303 is logged in Operations Manager

This article helps you fix an issue in which a wildcard matching rule fails and event ID 10303 is logged in System Center Operations Manager.

Original product version:   System Center 2016 Operations Manager, System Center 2012 Operations Manager, System Center 2012 R2 Operations Manager
Original KB number:   3004791


In the Operations Manager component for System Center 2016, System Center 2012 R2, System Center 2012, a wildcard matching rule fails, and the following event is logged in the event log:

Event Type: Error
Event Source: Health Service Modules
Event Category: None
Event ID: 10303
User: N/A
Computer: <ComputerName>
The Microsoft Operations Manager Expression Filter Module failed to process a data item and dropped it.

Error: 0x80004005

One or more workflows were affected by this.

Workflow name: <WorkflowName>
Instance name: <InstanceName>
Instance ID: {InstanceID}
Management group: <MG name>


This problem may occur if the length of the line for the match is longer than the Expression Filter can handle.



Before you modify the registry, follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.

To resolve this problem, follow these steps:

  1. Create the following registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Operations Manager\3.0\Modules\Global\ExpressionFilter

  2. Under this subkey, create a DWORD value.

  3. Type the MaxExpressionDepth name for the DWORD value.

  4. Assign a data value that is between 500 and 100000. The default value is 2000.


After you change the registry, the MonitoringHost.exe process may crash and you will see an event 4000 in the Operations Manager event log. In this case, try to use a different operator in the Rule filter. For example, try the Contains operator instead of using regular expression or wildcard. If it doesn't resolve the problem, contact Microsoft Support.