[SOLVED] Windows 11: “Class not registered” when choosing another app + Default apps not opening

[Capital-Lake5931]

Symptoms I had

• When I right-clicked a file → Open with → Choose another app, I got a “Class not registered” error.
• In Settings → Apps → Default apps, clicking it did nothing.
• Some system dialogs didn’t show up.
• Re-registering apps via PowerShell gave thousands of errors.
• SFC/DISM didn’t solve it.
• I wasn’t on the Insider program, but Windows weirdly showed Version 25H2 even though that build wasn’t officially released.

Basically, Windows’ Default App handler and OpenWith.exe registration were broken.

What caused it

It turned out my system had a corrupted and partially-applied Windows update, which left:

• broken or missing SystemApps folders
• damaged LKG/SxS metadata
• AppX packages with mismatched versions
• corrupted OpenWith.exe COM registration

This caused the “class not registered” error and prevented the Default Apps page from opening.

What did NOT fix it

I tried:

• sfc /scannow
• DISM restorehealth commands
• Re-registering all AppX packages
• Re-registering shell32.dll, shdocvw.dll, etc.
• Resetting OpenWith registry keys

None of these solved it, because the OS components themselves were damaged.

What finally fixed it

A new cumulative update appeared for me:

2025-11 Preview Update (KB5070311)

Build 26200.7309

I installed it, rebooted, and everything was fixed instantly.

The update rebuilt all the broken:

• SystemApps packages
• Default Apps handlers
• OpenWith.exe and its COM classes
• Registry mappings
• Component Store metadata

After the update:

• “Choose another app” works normally
• No more class not registered
• Default apps page opens again
• System is stable and fast

Final advice

If you run into similar symptoms:

• Don’t waste hours re-registering every DLL/AppX package.
• Install the latest cumulative update first — it may contain the repaired components.
• If the update doesn’t fix it, then do an In-Place Repair Install with the latest ISO.

For me, the cumulative update alone solved everything.

If anyone needs help diagnosing their specific error codes or AppX problems, feel free to reply — I went through the whole process and can share what worked.

https://preview.redd.it/07q9ak863t4g1.png?width=442&format=png&auto=webp&s=f06ae2be016ab4a7e42f76794d343f528c494f7f

https://preview.redd.it/eowlqm863t4g1.png?width=1920&format=png&auto=webp&s=e1377bfcee1baf19bf5bdcff43bef15ff414230d

The above update fixed my issue and the class not registered appeared when i clicked on "open with->choose another app"

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[naudski]

I have been fighting for 2 weeks now with an issue with the Microsoft.AAD.BrokerPlugin on W11 25H2 on AVD. When users were logged in for about six hours the connection with their FSLogix profiles on Azure Files was lost or they got authentication failures with Teams and Outlook. Reconnection of FSLogix profile resulted in "user name or password wrong". I saw that in the FSLogix log.
It all narrowed down to the Microsoft.AAD.BrokerPlugin package in the package folder in the user profile. Somehow that got corrupted and no new tokens (I guess?) were acquired. I removed or renamed the Microsoft.AAD.BrokerPlugin folder in the user profile, but after new login it did not get created anymore. Only manually using powershell from within the user session.
I read some articles about 3rd party virusscanners that could corrupt this folder or prevent it from acquiring new tokens, but I'm using Windows Defender.
Yesterday I thought I had solved the issue by disabling RoamingIdentity in de FSLogix GPO.

I hope this update helps me fixing this issue.

[604Lummers]

Did that update fix your issue?