Have you encountered an error message: Excel cannot open the file because the file format or file extension is not valid? In this video, we are going to show you 6 quick fixes to help you solve the problem. Let's get started! The first method is by changing Excel file extension. To do this, launch Microsoft Excel on your PC, head to the “File” section, and click “Export.” In the section, select “Change File Type” and click on the file with the error. Change the file extension and save the file. Fix two: Fix Excel cannot open the file by restoring the Previous Excel. Locate the infected file in your file’s explorer. Right-click the file and choose Properties from the menu. Head to “Previous Versions” bar. A list of previous versions shall be displayed, select one of them, and click “Restore” to recover it and click "Ok" The next method is using Open and Repair feature. Launch Excel at your computer and head to the files section. Click on “Open” and select browse from the side menu. Select the file you wish to use and expand the “Open” drop-down menu. Choose “Open and Repair option” Now choose Repair to fix it The forth method to open the file is by recovering unsaved Workbook. Launch MS Excel on your system and then click on the "File" tab. Now, go to the "Info" section. Click on the "Manage Workbook" option. Choose the "Recover Unsaved Workbook" option. Upon clicking the Recover Unsaved Workbook, Microsoft Excel will look for unsaved files then it will display them. From the displayed file, open the file and save it again. Another way to fix excel cannot open the file is by opening Safe Mode. Press the "Window + R" key to launch "Run Terminal”. When the Run Terminal launches, type excel /safe in the search field and hit the "Enter" button. When the Microsoft Excel launches in Safe Mode, click on the "File" tab and then click on "Options". Now, go to "Add-ins” section. Now, select the "COM Add-ins" option from the drop-down menu, and then click the "Go" button. Now, clear one of the add-ins from the displayed list and click on the "OK" button. The ultimate method is by using Tenorshare 4DDiG Data Recovery If the "Excel cannot open the file because the extension is not valid" problem is caused by file corruption rather than file compatibility, you need a professional file repair program to help you fix the problem. Tenorshare 4DDiG is a professional data recovery tool that can recover data from Windows, Mac, USB, SD Card, External Hard Drives, Digital Camera under various scenarios such as Disk Damage, Corruption, Disk Format, Update Failure, Accidentally Deletion, System Crash, Partition Loss and more. To recover corrupted Excel, just download and install 4DDiG on your computer and run it. As you can notice from the interface, 4DDiG can recover any corrupted data from local disks, external drives, desktop, recycle bin, selected folder and even from crashed computer. Now choose the location where the excel got corrupted and then click "Start" button to scan the selected area. It should take a while for 4DDiG to find out and repair corrupted excel file. After the scanning, you can find the files through the filter, file path, search, etc. Finally choose target files and click Recover to save them to a safe location. Hopefully these methods can help you to fix Excel cannot open the file. If you have any questions, just leave your comments below. See you next time!