CO_E_DECODEFAILED 0X8001013D: ACL decode failure fix

Cause 1: Corrupted registry permissions (most common)

This error usually happens when a program tries to read an Access Control List (ACL) from the Windows Registry but the ACL data is corrupted or the registry key has bad permissions. I've seen this most often after a failed software uninstall or a registry cleaner that went too far.

Here's how you fix it:

1. Press Windows Key + R, type regedit, and hit Enter.
2. In Registry Editor, click File > Export to back up your registry. Save it somewhere safe.
3. Navigate to the key that's causing the error. The error message usually points to a specific key or program. If you don't see one, try HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion — that's a common place for this error.
4. Right-click the key and select Permissions.
5. In the Permissions dialog, click Advanced.
6. Look at the Owner field at the top. It should say TrustedInstaller or SYSTEM. If it shows a user account or "Unknown", you've found the problem.
7. Click Change next to Owner, type SYSTEM, click Check Names (it should underline it), then click OK.
8. Check the box that says Replace owner on subcontainers and objects.
9. Click Apply, then OK.
10. Close Registry Editor and restart your computer. After restart, try whatever triggered the error again.

If the error goes away, you're done. If not, move on to Cause 2.

Cause 2: A specific app has a broken COM registration

Some apps register COM objects with bad ACLs during installation. Microsoft Office and Adobe products are common culprits. I once fixed this for a user whose Photoshop couldn't launch after a Windows update.

1. Press Windows Key + X and select Windows Terminal (Admin) or Command Prompt (Admin).
2. Type sfc /scannow and press Enter. Let it run — it checks system files. This might take 10-15 minutes.
3. After that completes, type DISM /Online /Cleanup-Image /RestoreHealth and press Enter. This fixes the component store. It can take 20-30 minutes.
4. Restart when done.
5. If the error still shows up, you need to find which app causes it. Open Event Viewer (Windows Key + R, type eventvwr.msc, Enter). Go to Windows Logs > Application. Look for error events with source "COM" or the error code. Double-click one and check the Details tab for the faulting application's path.
6. Once you know the app, uninstall it from Settings > Apps > Installed apps. Then reinstall the latest version from the official site.

Skip Cause 1 if you already tried it — don't repeat steps you don't need.

Cause 3: System file corruption in the COM infrastructure

If the first two causes didn't work, the COM subsystem itself might have a corrupted file. This is rarer, but I've seen it after a failed Windows Update or a disk error.

1. Run the System File Checker again, but this time with a deeper scan: open Command Prompt as admin and type sfc /scannow. Yes, again — sometimes it needs two passes to fix everything.
2. After that, check your disk for errors. Type chkdsk C: /f /r and press Enter. You'll get a message saying "Chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts?" Type Y and press Enter. Restart your computer — the scan will run before Windows loads. This can take over an hour on a large drive.
3. Once the disk scan finishes and Windows boots, try the operation again. If the error persists, you might need to do a repair install of Windows. Use the Windows Media Creation Tool to download an ISO and run setup.exe from inside Windows while keeping your files and apps. This replaces all system files without wiping your data.

I've rarely needed to go past this point. But if you still see the error, back up your data and consider a clean Windows install — that always kills this error for good.

Quick-reference summary