How to fix error C:\Program Files\Microsoft\Office\root\Office16\AppVlsvSubsystems64.dll

Question

I keep getting the error message above, how do I fix this? I need to have OUtlook on my PC

Answer 1

The error indicates a problem with the AppVIsvSubsystems DLL in the Office installation. The supported fixes are to repair Office, and if that fails, completely remove and reinstall Office so Outlook can work again.

Follow these steps in order:

1. Run a Quick Repair, then Online Repair of Office
   1. Open Control Panel in Windows.
   2. Select Uninstall a program.
   3. Find the Microsoft Office product in the list and select it.
   4. Select Change on the toolbar.
   5. In the dialog, choose Quick Repair, then select Repair and let it complete.
   6. Try starting Outlook.
   7. If the error persists, repeat steps 1–4, but this time choose Online Repair and then Repair. This requires an active Internet connection and performs a deeper repair.
2. If repair does not fix it, fully uninstall and reinstall Office If Quick Repair and Online Repair do not resolve the DLL error, the next step is to completely remove Office and then reinstall it:
   • Uninstall Office from Apps & Features or Programs and Features.
   • If normal uninstall fails or leaves Office in a broken state, use the dedicated Office uninstall tool (for example, o15-ctrremove.diagcab) as described in the referenced solution, then delete any remaining Office folders under C:\Program Files\Microsoft Office as done in the moderator solution.
   • Restart the PC.
   • Reinstall Office from the Microsoft 365 or Office account page and then start Outlook again.

These steps have been confirmed in similar cases to restore a working Office/Outlook when AppVIsvSubsystems DLL errors occur.

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References:

• Error: The application can't start because AppVIsvSubsystems32.dll is missing from your computer
• How do I get office 365 to work? - Microsoft Q&A
• Office 2021 desktop apps fail to open, cannot restore or uninstall - Microsoft Q&A