WMI Object Counter encountered an Invalid Class error in WMI query (4281802)

Symptom

A monitored server in SharePoint Diagnostic Manager may return an error similar to the following:

WMI Object Counter named ' ' encountered an Invalid Class error in WMI query for object ' '. This usually indicates that the WMI objects are not available on the target machine.

SharePoint Diagnostic Manager uses WMI to gather performance counters from monitored servers in a farm.

This issue can occur due to one of three reasons:

• Performance Monitor (perfmon) counters are not generated or available through WMI itself.
• SharePoint Diagnostic Manager Collection service account does not have sufficient permissions to interact with WMI on the monitored server.
• WMI synchronization is not occurring. The counters exist, but the WMI service is not handling them correctly.

It must first be determined if the WMI counters are not generating properly on the monitored machine. To confirm that WMI counters can be found and collected natively, you can use the WBEMTEST utility in Windows. It will return a fairly clear error message if the counters do not load, which you will need to change in order to resolve the issue. To perform this native test, please do the following:

1. On the server hosting the monitored SQL server instance, log in using the same account that the SharePoint Diagnostic Manager Collection service runs as.
2. Click Start > Run in Windows, then type WBEMTEST to open the utility.
3. Connect to \root\cimv2 on the initial pane of the utility. In some cases, you may have to change this value from \root\default. An error message when connecting typically indicates a permissions issue. The error message itself should indicate what is the cause.
4. If this test succeeds, it should be repeated on the machine hosting the SharePoint Diagnostic Manager Collection service. A failure or error during this second test will indicate a communication issue to the target server and the error message should indicate what the failure is. 

The following are the basic permission requirements for the monitored server to be able to collect the necessary counters.

• Grant Read & Execute permissions to the SQL server service account on C:\winnt\system32\wbem. The specific path to this folder may differ depending on the operating system.
• Grant Read & Access permissions for the HKLM\SOFTWARE\MICROSOFT\WINDOWS NT\WBEMPERF registry key. On some operating systems, this key is HKLM\SOFTWARE\MICROSOFT\WBEM. NOTE: As a best practice, back up the registry before making any changes.
• Add the SQL server service account to the Performance Monitor Users domain built-in group. This group may not be available on some operating systems.

Assuming the connection succeeds, it's likely that the issue rests with the WMI counters themselves and not with accessing them. Use the following steps in WBEMTEST to confirm this:

1. Connect to \root\cimv2, select the button for ENUM CLASSES, then choose the Recursive option. Don't type anything on the search field, just click OK. This should enumerate all of the recursive counters in WMI.
2. Scroll down in the alphabetic list of classes and ensure that there are Win32_Perf classes listed.

If the performance counters do not appear in the list, one possible cause that may need to be ruled out is that the monitored machine's WMI's ADAP process is not synchronized with the WMI counters on the machine due to a service account permissions issue or a timeout in the attempt of synchronization. The WMI ADAP can be resynced with the WMI counters by opening a command prompt on the monitored machine and running the following set of commands:

WINMGMT.EXE /CLEARADAP
WINMGMT.EXE /RESYNCPERF
NET STOP WINMGMT
NET START WINMGMT

NOTE: In Windows 2008 and later, the /clearadap switch does not function. You can attempt the two following resynchronization commands instead:

wmiadap /f
wmiadap /r

If this counter still cannot be generated, a final option would be to restart the computer hosting the monitored server. This creates the WMI counters from scratch and may resolve this issue.

Should the symptom persist, there is an issue with the WMI counters that will need to be resolved with Microsoft. Microsoft offers a WMI Diagnosis Utility to assist with the diagnosis of this issue.