If you’re seeing the “Microsoft Excel may be damaged or incomplete” error, there are a few things you can try to fix it. You can try the following solutions, but first, make sure Excel can be launched successfully from the Applications folder (not from a shortcut or a file).

If you’re experiencing problems with Microsoft Excel, see if restarting your Mac in Safe Mode solves the problem. If it does, clear out any Startup Items on your device and try launching the app again!

Method 1. Update the Microsoft Excel App to the Latest Version

The first thing you should do is make sure Excel is up to date. To do this, open the Microsoft Excel application and click on Excel > Preferences. In the window that appears, click on the “Check for Updates” button.

If there are any updates available, install them and then try launching Excel again. If the problem persists, move on to the next solution.

1. Open a web browser and go to the Microsoft website’s Microsoft Office for Mac page.
2. Now, go to the most recent version of Office and click on Update Package (in front of Excel) to download the package.
   
3. Open the package and follow the on-screen instructions to begin the update process.
4. After installing the update package, see if you can open Microsoft Excel without getting a damaged or incomplete error message.

Method 2. Keep macOS Up to Date

Next, you should check to see if your version of macOS is up to date. To do this, click on the Apple icon in the top left corner of your screen and select “About This Mac”. In the window that appears, you will see the version of macOS that you are currently running. If it is not the latest version, click on the “Software Update” button and install any available updates.

Once your macOS is up to date, try launching Excel again. If you’re still seeing the same error message, move on to the next solution.

1. Click on the Apple menu in the top right corner of your screen, and then choose System Preferences from the drop-down interface.
   
2. Click on the App Store button.
   
3. Click on the Show Updates button.
   
4. Switch to the Updates tab on top of the new window. Wait for your system to find any new updates to install, and then click on the Update button.
   
5. A prompt will show up on the side of your screen. Click the Restart button or wait for the timer to finish counting down. Your computer will reboot and apply any new updates.
   

Note that some newer macOS systems may allow you to update directly from the System Preferences. If you have the “Software Update” button, click on it and check for new updates there!

Method 3. Clear Microsoft Excel Cache on Mac

As we mentioned before, Excel uses a cache to speed up its processes. If this cache becomes corrupt, Excel will not launch normally. To clear the Excel cache on your Mac, follow these steps:

1. Go to the Library folder in the Finder on your Mac. If the Library folder isn’t visible, right-click on an empty area, select Show View Options, and check the Show Library Folder box.
2. Alternatively, you can access the Library folder by pressing Command + Shift + G and typing ~/Library.
3. Now, drag the following folders to your Mac’s desktop (as per your macOS version):
   • Big Sur: ~/Library/Containers/Microsoft Excel
   • Catalina: ~/Library/Containers/ com.microsoft.Excel
4. After you’ve completed the previous step, restart your Mac and open the Microsoft Excel application to see if it’s working properly.

Method 4. Copy the Microsoft Excel Application to the Applications Folder

The error message may appear in the Microsoft Excel application file that has been moved from Mac’s applications folder, either by you or by another app on your system. Moving the Microsoft Excel application file back to the applications folder may resolve the issue in this case.

1. To begin, open your Mac’s Applications folder and see if the Microsoft Excel.app file is present.
2. If the Excel app does not appear in your folder, open the Spotlight search by pressing Command + Space Bar or clicking the search icon on the menu bar.
   
3. Now, in the search box, look for Microsoft Excel.app, and if it’s there, drag it to the Applications folder.
4. Launch the software from the Applications folder to see if the Microsoft Excel application is free of the “damaged or incomplete” error.

Method 5. Reinstall the Microsoft Excel App on your Mac

If Excel is still not launching correctly, you may need to reinstall the app on your Mac. To do this, follow these steps:

1. Open your Mac’s Applications folder, and then hold the Control key on your keyboard while you click on Microsoft Excel.
2. Select Move to Bin from the context menu.
3. Navigate to the Library folder. If the Library folder isn’t visible, right-click on an empty area, choose Show View Options, and check Show Library Folder.
4. In the Library folder, delete the files or folders related to Excel in the following subdirectories:
   • ~Library/Preferences
   • ~Library/LaunchDaemons
   • ~Library/PrivilegedHelperTools
   • ~Library/Preferences
   • ~Library/Application Support
   • ~Library/Receipts
   • ~Library/Automator
   • ~Library/Application Script
     
5. After the process is complete, restart your Mac and download Excel from the Office website again. Follow all on-screen instructions to sign in with your Office account and see if you’re able to launch Excel.

• Excel may not launch on your macOS if the installation is damaged, outdated, or if your system is having problems
• If Excel is not located in your Applications folder, you should copy it there
• Make sure your Mac is up-to-date with the latest updates
• Always update the Excel application to the new version
• If you’re unable to fix Excel, try to reinstall it on your Mac. You can download it from Microsoft directly.