Share via

Unable to open MS Office 365 apps

Richard Baskin 0 Reputation points
2026-05-09T23:35:54.8733333+00:00

when I try to open any Office app I get the following error:

C:\Program Files\microsoft

Office\root\Office16\AppVlsvSubsystems64.dll is either not designed to run on Windows or it contains an error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support. Error status 0xc000012f

I was able to use the apps an hour ago.

What should I do since the software was loaded on the computer when I got it?

Microsoft 365 and Office | Install, redeem, activate | Other | Other
0 comments

2 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Norah-L 6,685 Reputation points Microsoft External Staff Moderator
    2026-05-10T05:16:26.2566667+00:00

    Good day Richard Baskin!

    Based on your description, your Office apps suddenly started an error (0xc000012f) related to a DLL file when opening, even though they were working normally earlier and came preinstalled on your device.

    This type of behavior might be linked to an issue where an Office component or supporting system library (such as the Visual C++ Redistributables) isn’t loading properly.

    You can try the steps below to resolve it:

    1. Stop any stuck Office installation Press Ctrl + Shift + Esc to open Task Manager, then check if OfficeSetup (or a similar process) is running. If found, select it and click End task.
    2. Reinstall Visual C++ Redistributables

    Download and install the Latest Supported Visual C++ Redistributable Downloads. To choose the correct version, go to Settings > System > About and check System type:

    • If it shows 32-bit, install x86
    • If it shows 64-bit, you can install both x64 and x86 to ensure compatibility across all components
    1. If the issue continues, reinstall Microsoft 365 / Office

    Please follow the Q&A Assist method to reinstall Microsoft 365 / Office.

    Tip: If you’re not sure which reinstall method applies, try signing in to the Microsoft account you used when setting up the device first, then check under Services & subscriptions to see if your Office product is listed there. If it appears, you can reinstall it directly from that page; if not, you may need to use the Microsoft Store or the original setup method that came with your device.

    See more: Reinstall Office or Microsoft 365 in your Office Pre-installed PC (for personal)

    Hope this helps. Please let me know how it goes or if you need further support!

    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

    Was this answer helpful?

  2. AI answer

    2026-05-09T23:36:04.8166667+00:00

    The error indicates a corrupted or broken Office Click-to-Run/App-V component (AppVIsvSubsystems DLL). Use the following steps in order:

    1. Run a Quick Repair, then Online Repair
      1. Open Control Panel in Windows.
      2. Select Programs > Programs and Features (or Uninstall a program).
      3. Find the Microsoft Office/Microsoft 365 entry in the list and select it.
      4. Choose Change (or Modify), then select Quick Repair and run it.
      5. After it completes, try opening an Office app.
      6. If the error persists, repeat steps 1–4 but this time choose Online Repair and complete it. This will reinstall Office components and usually fixes missing/corrupt AppV DLL issues. An active Internet connection is required.
    2. If repair does not work, fully uninstall and reinstall Office If Quick/Online Repair do not resolve the problem, the installation is likely badly corrupted.
      1. Uninstall Office from Apps & Features or Programs and Features.
      2. Restart the computer (not just shut down/start).
      3. Reinstall Office from the original source:
        • If Office came preinstalled, sign in to the Microsoft account or OEM portal where the license is associated and download/install again, or
        • Use the Office installer provided by the device vendor.
      In more stubborn cases (where uninstall/reinstall fails or Office is half‑removed), support may use the o15-ctrremove.diagcab Office uninstaller tool to completely remove remnants and then reinstall Office cleanly.

    If these steps fail (for example, repair/uninstall won’t run or the product no longer appears in the installed apps list but reinstall still fails), contact Microsoft Support or the PC manufacturer’s support and mention that the AppV/AppVIsvSubsystems DLL is corrupted and that a full removal with the Office uninstaller tool followed by a clean reinstall is needed.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.