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Excel Desktop Add-ins Not Loading (Works in Excel Web)

stephanie garciaherreros vega 0 Reputation points
2026-05-29T22:29:03.53+00:00

I am unable to load any Office Add-ins in Excel Desktop. When I go to Insert → Add-ins, I receive an error stating that one or more add-ins could not be loaded.

This issue occurs with all add-ins, not just a specific one. However, the same account works correctly in Excel for the web, where I can install and use add-ins without any problems.

I have already tried multiple troubleshooting steps, including repairing Office, clearing the Office cache, resetting network settings, and reinstalling WebView2. None of these actions resolved the issue.

This suggests the problem is related specifically to the Excel Desktop environment on my device.

Microsoft 365 and Office | Excel | For home | Windows
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  1. Mite Suo 5,180 Reputation points Independent Advisor
    2026-05-30T01:14:48.5866667+00:00

    Hi, I'm Mite and here to help.

    Since the same account works correctly in Excel for the web, this does not look like a general account or add-in permission issue. It points more toward the Excel Desktop environment on this device.

    Please try the following checks:

    1. In Excel Desktop, go to File > Account > Account Privacy > Manage Settings and make sure connected experiences are enabled. Office Add-ins may fail to load if Office is not allowed to connect to online services.
    2. Check the Windows date, time, and time zone. Close Office, then go to Windows Settings > Time & language > Date & time and make sure the date, time, and time zone are correct. Microsoft’s Office Add-ins troubleshooting documentation notes that incorrect system time can cause add-in manifest verification problems.
    3. Test Excel in Safe Mode. Press Windows + R, type excel /safe, and try Insert > Add-ins again. If it works in Safe Mode, disable unnecessary COM add-ins under File > Options > Add-ins.
    4. Update Office from File > Account > Update Options > Update Now. If this started after a recent Office update, also consider testing a rollback to a previous stable build, especially if this is managed by an organization.
    5. Clear the Office Web Add-in cache again by closing all Office apps and deleting the contents of: %LOCALAPPDATA%\Microsoft\Office\16.0\Wef
    6. If this is a work or school account, ask your Microsoft 365 admin to check whether Office Store add-ins, integrated apps, or user-owned apps are restricted by policy.
    7. Check whether firewall, proxy, VPN, SSL inspection, or security software is blocking Excel Desktop from reaching Office Add-ins/Microsoft Store endpoints.
    8. Create a new Windows user profile on the same device and test Excel add-ins there. If add-ins work in the new profile, the issue is likely with the original Windows/Office user profile.

    Because add-ins work in Excel for the web, the focus should be on the desktop Office environment, connected experiences, local Office cache, WebView2/WEF cache, security policy, or the Windows user profile.

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  2. AI answer

    2026-05-29T22:29:22.35+00:00

    Because add-ins work in Excel for the web but fail for all add-ins in Excel Desktop on a single device, the issue is most likely with the local Office desktop environment (configuration, policies, or update state), not the account or the add-ins themselves.

    Try the following targeted steps on the affected PC.

    1. Confirm Excel and Office are fully updated
    • Make sure the desktop Excel is on a supported and up-to-date build. Some known issues with add-in activation and updates have been fixed in recent builds.
    • Install all available Office updates, then restart the device and test add-ins again.
    1. Check for known add-in activation/update issues
    • There is a known issue where Office Add-ins can fail to update or activate correctly, leaving them unavailable.
    • Recommended actions:
      1. Restart Excel.
      2. Retry loading or updating the add-in after some time.
      3. If the issue persists, collect diagnostic information (session logs, network traces) and provide it to support.
    1. Check for configuration or policy blocks
    • When add-ins fail to load, sometimes an ADD-IN INFORMATION bar appears at the top of the task pane indicating that Microsoft 365 has been configured to block certain add-ins.
    • If any such information bar appears, this indicates a tenant or policy configuration issue rather than a problem with the add-in itself. In that case, contact the Microsoft 365 administrator to review add-in policies as described in Errors in an ADD-IN INFORMATION box.
    1. Test for WebView2 / security software interference
    • If the error text or logs show E_ACCESSDENIED (0x80070005) or similar access-denied errors when add-ins attempt to start, antivirus or endpoint security software may be blocking the WebView2 process that Office uses to host add-ins.
    • To resolve this, add exclusions in the antivirus for:
      • The Office root folder, for example: C:\Program Files\Microsoft Office\root\Office16
      • And, if needed, the WebView2 process, for example: C:\Program Files (x86)\Microsoft\EdgeWebView\Application[latest installed version]\msedgewebview2.exe
    • After adding exclusions, restart Excel and test add-ins again.
    1. Verify add-ins are not crashing Excel
    • Some add-ins can be disabled by Data Execution Prevention (DEP) or cause instability.
    • Start Excel in Safe Mode (for example, run excel /safe), then go to File → Options → Add-Ins and review which add-ins are enabled.
    • If Excel runs more reliably in Safe Mode, disable add-ins one by one (COM Add-ins and Excel Add-ins) and then restart Excel normally to identify any problematic add-in.
    1. If Excel opens but add-ins still never load
    • Follow the isolation steps for add-ins:
      1. In Excel, select File → Options → Add-Ins.
      2. In Manage, select COM Add-ins → Go.
      3. Clear all COM add-ins, select OK, and restart Excel.
      4. If the problem persists, repeat and test with Excel Add-ins in the Manage list.
    • If Excel behaves normally but Office Add-ins (task pane add-ins from the Store or admin-managed) still fail to load, this further points to a WebView2, policy, or update issue as above.
    1. If none of the above resolves it
    • Ensure the device time and date are correct, as incorrect system time can interfere with manifest validation when installing or loading add-ins.
    • If the issue continues after updates, antivirus exclusions, and add-in isolation, gather logs (including any error codes shown in the add-in error dialogs) and contact Microsoft Support for deeper investigation, as recommended in the add-in troubleshooting guidance.

    References:

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