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How to Fix Microsoft 365 Copilot Cannot Create a New Excel Workbook
Question details
Users are encountering an error where Microsoft 365 Copilot is unable to generate a new blank Excel workbook from its interface.
- Product
- Microsoft 365 Copilot / Microsoft Excel
- Device & OS
- not provided
- Scenario
- Attempting to create a new Excel spreadsheet directly using the Microsoft 365 Copilot app or launcher.
- Observed behavior
- Copilot displays an invalid file format or file extension error (often referencing a corrupted file), despite the standalone Excel application opening and functioning normally.
Verify your current Microsoft 365 Copilot version in the application settings, as this is a known bug in specific builds. Ensure your standalone Excel application is updated and functioning correctly before proceeding with workarounds.
Create the Workbook Directly in Excel
Bypass the Copilot app launcher by creating your workbook manually in Excel, which avoids the file generation bug.
This error is a known issue frequently occurring in Microsoft 365 Copilot versions 18.2502.1041.0 and 18.2501.1284.0. Because the issue persists across multiple computers and resetting the app does not resolve it, utilizing Excel directly is the most reliable workaround until Microsoft releases a patch.
Open the Microsoft Excel application directly from your Windows Start Menu, macOS Launchpad, or desktop shortcut instead of using the Copilot launcher.
Click on 'Blank workbook' on the Excel home screen to generate a new spreadsheet without encountering the file format error.
Once your new workbook is open, navigate to the 'Home' tab on the Excel ribbon and click the 'Copilot' icon to open the AI assistant pane.
Return to the Microsoft 365 Copilot interface, click the 'Feedback' or 'Help' icon, and report the 'invalid file format' error to Microsoft to help expedite a fix.
Use Microsoft 365 on the Web
Use the web-based version of Excel and Copilot, which operates independently from your local desktop application's bugs.
Experience Seamless AI Productivity with WPS Office
If Microsoft 365 Copilot bugs are disrupting your workflow, consider switching to WPS Office. It provides a lightweight, highly compatible alternative with built-in WPS AI to help you generate formulas, analyze data, and create documents effortlessly without version-specific crashes.
- 1. Download and Install: Visit the official WPS Office website to download and install the free suite on your device.
- 2. Open WPS Spreadsheets: Launch the application and select 'Spreadsheets' to create a new, fully compatible workbook instantly.
- 3. Launch WPS AI: Click the 'WPS AI' icon located on the main ribbon to start interacting with your spreadsheet using powerful AI tools.
Frequently Asked Questions
Why does Microsoft 365 Copilot say my new Excel file format is invalid?
This is a known bug in specific versions of the Copilot app (such as 18.2502.1041.0). The app attempts to generate a temporary file (often named 'Book 2.xlsx') but fails to format it correctly, resulting in an invalid file extension or corruption error.
Will reinstalling Microsoft 365 fix the Copilot workbook creation error?
No, because this issue has been replicated across multiple computers and accounts. Reinstalling or resetting the local application typically does not resolve it, as it requires a version update or patch directly from Microsoft.
How can I still use Copilot if the 'New Workbook' button is broken?
You can easily bypass this bug by opening your standalone Excel application manually, clicking 'Blank workbook', and then launching the Copilot assistant directly from the 'Home' tab on the Excel ribbon.
