When you double-click on an Excel file and it doesn’t open, there are a number of potential causes or solutions that you can try:

1. Check if all Office programs are closed as the file may be open in another window
2. Check your system for potential office updates and security patches
3. Check if an add-in is causing the issue or disabling it as a test
4. Check if your system is virus free
5. Ensure that you have proper permissions to access the file
6. If the above troubleshooting steps do not resolve the issue, you might need to repair or reinstall Office