Power Pivot Excel Add In - The type initializer of Module threw an exception

First check whether Excel disabled Power Pivot; if it appears under Disabled Items, re-enable it before attempting an Office repair.

1. Restore and reload Power Pivot

1. Close all Excel workbooks except one blank workbook.
2. Go to File → Options → Add-ins.
3. At the bottom, set Manage to Disabled Items, and select Go.
4. If Microsoft Office Power Pivot appears:
   • Select it.
   • Select Enable.
   • Close and restart Excel.

Excel can place Power Pivot in Disabled Items after an unexpected shutdown or when it determines that the add-in is destabilizing Excel.^1^

Then verify that it is loaded:

1. Return to File → Options → Add-ins.
2. Set Manage to COM Add-ins, then select Go.
3. Select Microsoft Power Pivot for Excel, and select OK.
4. Restart Excel and test Power Pivot → Manage.

If Power Pivot remains selected after restarting but Manage still produces the <Module> initializer error, proceed to repair rather than repeatedly toggling the add-in.

2. Repair the Microsoft 365 installation

The message identifies an initialization failure but does not expose the underlying failure by itself; a .NET TypeInitializationException wraps the original exception, which is available through its inner exception.^2^

Repair the installed Office components:

1. Close every Office application.
2. In Windows 11, right-click Start → Installed apps.
   In Windows 10, right-click Start → Apps and Features.
3. Locate Microsoft 365, select the three-dot menu if shown, and choose Modify.
4. For a Click-to-Run installation, select Online Repair → Repair.
   • Online Repair is preferable here because it performs a more complete repair than Quick Repair.
5. Restart Windows after the repair, open Excel, and test Power Pivot → Manage again.

Online Repair repairs the entire Office suite, including Excel and its installed Power Pivot components.^3^

3. Isolate another COM add-in only if repair does not help

1. Press Windows+R, enter excel /safe, and select OK.
2. In Excel, open File → Options → Add-ins.
3. Select COM Add-ins → Go.
4. Record the currently enabled add-ins, then clear all third-party COM add-ins.
5. Close Safe Mode and restart Excel normally.
6. Keep Power Pivot enabled and re-enable the other add-ins one at a time, restarting Excel after each change.

Microsoft documents this one-at-a-time process for identifying a conflicting COM add-in.^4^

If the error occurs only with one workbook

Check whether the workbook’s Data Model was created by a newer Excel/Power Pivot version. Microsoft documents that a newer Data Model cannot be loaded or edited with an older Power Pivot version; opening it with the matching or newer Excel version is required.^5^

If the error occurs even with a new blank workbook after Online Repair and third-party add-in isolation, collect the complete error details—particularly the inner exception—from the error dialog or Windows Event Viewer and provide the Excel version/build shown under File → Account → About Excel. Those details are needed to distinguish a missing component from a build-specific failure.

References

1. Start the Power Pivot add-in for Excel | Microsoft Support
2. TypeInitializationException Class (System) | Microsoft Learn
3. [Windows 11](https://support.microsoft.com/office/lifecycle/repair-an-office-application)
4. Excel not responding, hangs, freezes or stops working
5. Power Pivot error: “Initialization of the data source failed” | Microsoft Support