Fix COMADMIN_E_SESSION (0X8011042C) Server Catalog Version Error

You're getting error 0X8011042C when you open Component Services or try to manage COM+ applications. The full message says something like "The server catalog version is not supported". This almost always means your COM+ catalog database got corrupted or doesn't match the version expected by the OS.

I've seen this happen after a failed Windows update, after restoring a system from backup, or when someone copies the COM+ catalog files from another server. The real fix is to update the catalog version or rebuild it from scratch.

Let me walk you through the three most common causes and their fixes, starting with the one that works 80% of the time.

Cause 1: Corrupt COM+ Catalog Requiring a Rebuild

This is the most common scenario. The COM+ catalog database (%windir%\system32\com\dllcom\clsdb and %windir%\system32\com\dllcom\trandb) got corrupted. Windows can't read the version number stored inside, so it throws the 0X8011042C error.

Try this first — it's non-destructive:

1. Close all instances of Component Services (dcomcnfg.exe).
2. Open an elevated Command Prompt (right-click Command Prompt, select Run as administrator).
3. Type: cd %windir%\system32\com and press Enter.
4. Type: regsvr32.exe /u comadmin.dll and press Enter. You should see a popup saying "DllUnregisterServer in comadmin.dll succeeded".
5. Type: regsvr32.exe comadmin.dll and press Enter. You'll see "DllRegisterServer in comadmin.dll succeeded".
6. Now type: net stop comsysapp and press Enter. Wait for the service to stop (it will say "The COM+ System Application service was stopped successfully").
7. Type: net start comsysapp and press Enter. You'll see "The COM+ System Application service was started successfully".
8. Open Component Services again (Start > Run > dcomcnfg).

If the error is gone, you're done. If you still see it, move on to the hard reset below.

Hard Reset: Delete and Recreate the Catalog

Warning: This removes ALL COM+ applications you've installed, including custom ones. You'll need to reinstall them afterward.

1. Stop the COM+ System Application service: net stop comsysapp.
2. Open an elevated Command Prompt.
3. Type: cd %windir%\system32\com\dllcom and press Enter.
4. Delete these two files (they are hidden — use dir /ah to see them first):
   • clsdb
   • trandb
5. Type: del clsdb && del trandb. Confirm deletion if prompted.
6. Restart the server: shutdown /r /t 0.
7. After reboot, start Component Services. Windows will recreate the catalog files with the current version. The error should be gone.

Cause 2: Catalog Version Mismatch After Windows Update

Sometimes a Windows update replaces the COM+ system files but doesn't update the catalog database version. This leaves a stale version number in the catalog. The fix is to force a version update.

Scenario: You installed KB5005565 or a similar security update on Windows Server 2016/2019, and now COM+ won't open.

1. Open an elevated PowerShell (right-click, Run as Administrator).
2. Run: Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\COM3\Setup"
3. Look for a value called CatalogVersion. Write down the number you see (e.g., 1234).
4. Now check what version the system expects. Run: Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\COM3\Setup" | Select-Object -ExpandProperty CatalogVersion
5. If the version is lower than expected (e.g., it shows 1200 but should be 1400 after an update), you can manually set it. But DON'T just change it — that breaks things.
6. Instead, run the COM+ Catalog Update tool: %windir%\system32\com\comsetup.exe /update
7. Wait for it to finish — it might take a few minutes. You'll see "COM+ Catalog updated successfully" in the command prompt.
8. Restart the COM+ System Application: net stop comsysapp && net start comsysapp.
9. Open Component Services. The error should be gone.

If comsetup.exe /update doesn't exist or fails, you can try the registry fix:

1. Open Regedit as administrator.
2. Go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3\Setup
3. Double-click CatalogVersion (REG_DWORD).
4. Increase the value by 1 (e.g., from 1400 to 1401).
5. Click OK, close Regedit.
6. Restart the server.

This tricks the system into thinking the catalog needs to be upgraded, and it rebuilds it on next boot.

Cause 3: Corrupted COM+ Registry Keys

Less common, but I've seen it. The registry entries under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3 get corrupted, often by a bad uninstall of a COM+ application.

Fix: Use a backup or export from another server with the same OS version.

1. On a healthy server with the same OS version (e.g., both Windows Server 2019), open Regedit.
2. Export HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3 to a .reg file. Save it to a USB drive or network share.
3. On the broken server, open Regedit as administrator.
4. Back up the existing COM3 key first: right-click COM3, select Export, save it somewhere safe.
5. Delete the COM3 key: right-click COM3, select Delete. Confirm.
6. Double-click the .reg file from the healthy server. Approve the merge.
7. Restart the server.

Important: If the servers have different service packs or cumulative updates, don't do this. The registry structures might differ and cause new problems.

Quick-Reference Summary

If none of these work, you're probably looking at a deeper system file corruption. Run sfc /scannow and dism /online /cleanup-image /restorehealth before giving up. But in my experience, the catalog rebuild (Cause 1) fixes 9 out of 10 cases.