Fix ERROR_NO_EVENT_PAIR (0X00000244) on Windows Server
This error pops up when a server or cloud app can't pair an event with its handler. Usually a misconfigured COM or threading issue.
When This Happens
You're managing a Windows Server 2016 or 2019 box running a custom cloud service or legacy COM+ application. Suddenly, the service stops responding. Event Viewer shows ERROR_NO_EVENT_PAIR (0X00000244). I've seen it most often after a reboot following a failed Windows Update KB5001342 on Server 2016, or when someone messed with the COM+ catalog permissions.
Root Cause
This error means the system can't match an event notification with its listening handler. In simpler terms: something (usually a COM component or a threaded service) registered an event sink, but the connection between the event source and the sink got broken. Happens when a DLL or OCX gets unregistered or corrupted, or when a threading model mismatch exists between the client and server. For example, an STA thread trying to fire an event to an MTA handler without proper marshaling.
Fix It
Step 1: Re-register the COM components
Open an elevated command prompt and run:
regsvr32 /u [YourCOMComponent.dll]regsvr32 [YourCOMComponent.dll]Do this for every DLL related to your app. I had a client last month whose entire print queue died because the print spooler's COM registration got hosed by a bad .NET update. Re-registering fixed it flat.
Step 2: Check the threading model
If re-registering doesn't help, the problem is often a threading mismatch. Open the Component Services console (COM+). Find your application, right-click Properties, go to the Identity tab. Set the identity to Interactive User for testing. But the real fix is to ensure the component's threading model in the registry matches what the client expects. Look under HKEY_CLASSES_ROOT\CLSID\{YourCLSID}\InprocServer32 for the ThreadingModel value. If it says Apartment but your client uses an MTA, change it to Both.
Step 3: Reset the COM+ catalog
If it's still broken, nuke the COM+ catalog and rebuild it. Run these commands as admin:
net stop comsysappcd %windir%\system32\comregsvr32 /i comsvcs.dllnet start comsysappThis resets all COM+ applications to their defaults. You'll lose custom configurations, so document them first. But I've seen this clear up the 0x244 error on a file server that had a corrupted COM+ log.
Step 4: Update or reinstall the .NET Framework
Sometimes the event pair problem traces back to a broken .NET installation. Run the .NET Framework Repair Tool from Microsoft, or uninstall and reinstall the relevant .NET version (3.5, 4.x, or 4.8) via Server Manager. On a Server 2012 R2 box I worked on, a corrupted .NET 3.5 caused this exact error in a legacy cloud sync service.
Still Stuck?
If none of these steps work, check the Windows Application Event Log for additional error codes right before or after 0x00000244. Look for 0x80040201 or 0x80070005 (access denied). That points to permissions. Also verify that the DCOM user account (usually NETWORK SERVICE or LOCAL SERVICE) has read+execute rights to the component's DLL file. Use icacls to check:
icacls C:\Path\To\YourComponent.dllIf the account can't even see the file, grant it RX permission. But don't take my word for it—test the fix in a non-production environment first. I've learned that the hard way.
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