How to Fix Excel Power Query Keeps Crashing with Error 0xC000026F

Microsoft Excel Power Query is a powerful data transformation and import tool used for cleaning, reshaping, and combining data from multiple sources. It is widely used in business environments for data analysis and reporting. However, some users encounter crashes when using Power Query, often accompanied by Error 0xC000026F. This error typically causes Excel to close unexpectedly during data refresh, transformation steps, or when loading queries.

Error 0xC000026F in Excel Power Query is usually related to corrupted Office installation files, problematic add-ins, damaged system components, memory conflicts, outdated builds, or issues with external data sources. Since Power Query relies heavily on Excel’s core engine and system libraries, resolving this issue requires checking both Office and Windows configurations.

This guide explains how to fix Excel Power Query keeps crashing with Error 0xC000026F in Windows 11 using structured troubleshooting steps.

How to Fix Excel Power Query Keeps Crashing with Error 0xC000026F

Follow the solutions below in order until Power Query functions without crashing.

1. Restart Excel and Windows

Temporary glitches may trigger application crashes.

1. Close Microsoft Excel completely.
2. Press Ctrl + Shift + Esc to open Task Manager.
3. Ensure Excel is not running in the background.
4. Restart your computer.
5. Open Excel and test Power Query again.

Restarting clears temporary memory conflicts.

2. Update Microsoft 365 or Office

Outdated builds may contain bugs affecting Power Query.

1. Open Excel.
2. Click File.
3. Select Office Account.
4. Click Update Options, then choose Update Now.
5. Install any available updates.
6. Restart Excel after updating.

Keeping Office updated improves stability and compatibility.

3. Disable Excel Add-ins

Conflicting add-ins may cause Power Query crashes.

1. Open Excel.
2. Click File, then select Options.
3. Choose Add-ins.
4. Click Go next to Manage COM Add-ins.
5. Uncheck all add-ins.
6. Restart Excel and test Power Query.

If the issue is resolved, re-enable add-ins one by one to identify the problematic one.

4. Repair Microsoft Office Installation

Corrupted Office files can cause runtime errors.

1. Press Windows + I to open Settings.
2. Click Apps, then select Installed apps.
3. Locate Microsoft 365 or Office.
4. Click the three-dot menu and select Modify.
5. Choose Quick Repair first.
6. If the issue persists, select Online Repair.
7. Restart your computer after completion.

Repairing Office replaces damaged components affecting Power Query.

5. Run Excel in Safe Mode

Safe Mode disables add-ins and custom settings.

1. Press Windows + R.
2. Type excel /safe and press Enter.
3. Open your workbook.
4. Test Power Query functionality.

If it works in Safe Mode, the issue is likely configuration-related.

6. Increase Virtual Memory

Memory limitations may trigger crash errors.

1. Press Windows + S, type Advanced system settings, and open it.
2. Under Performance, click Settings.
3. Go to the Advanced tab.
4. Click Change under Virtual memory.
5. Select Custom size.
6. Set initial and maximum values higher than current.
7. Click Set, then OK, and restart your PC.

Increasing virtual memory can prevent crash-related memory faults.

7. Run System File Checker (SFC)

Corrupted Windows system files may cause runtime exceptions.

1. Press Windows + S, type cmd.
2. Right-click Command Prompt and select Run as administrator.
3. Type the following command and press Enter:sfc /scannow
4. Wait for the scan to complete.
5. Restart your computer.

SFC repairs damaged system files.

8. Run DISM to Repair System Image

If SFC does not resolve the issue, use DISM.

1. Open Command Prompt as administrator.
2. Type the following command and press Enter:DISM /Online /Cleanup-Image /RestoreHealth
3. Wait for the process to complete.
4. Restart your PC.

DISM repairs deeper system image corruption.

9. Check Data Source Connections

Corrupted or unstable external data sources may cause crashes.

1. Open Excel and go to Data.
2. Click Queries & Connections.
3. Review each connection for errors.
4. Remove or recreate problematic connections.
5. Refresh queries one at a time.

Testing connections individually can identify the faulty source.

10. Reinstall Microsoft Office

If none of the above solutions work, a full reinstall may be required.

1. Press Windows + I to open Settings.
2. Click Apps, then select Installed apps.
3. Locate Microsoft 365 or Office and click Uninstall.
4. Restart your computer.
5. Download and reinstall Office from the official Microsoft website.
6. Activate and test Power Query again.

Reinstallation ensures a clean Office environment.

Conclusion

Excel Power Query crashing with Error 0xC000026F in Windows 11 is typically caused by corrupted Office files, conflicting add-ins, outdated builds, memory limitations, damaged system components, or unstable data connections. By updating Office, disabling add-ins, repairing installation files, increasing virtual memory, and running system diagnostics, you can restore stable Power Query functionality.