Excel cannot open the file because the file format or extension is not valid
This error message is encountered in the following scenarios:
The file has become corrupt or damagedThe file is not compatible with the Excel version.
The error in Excel can be fixed by any one of the following 3 methods described below. Let’s explore the above methods in a bit of detail!
1] Change the file extension
If you cannot open the Excel file from its location, simply open any Excel file and click the File tab. Then, go to Open > Browse and select the file giving error. Under the File name field, change the extension from ‘.xlsx’ to ‘.xls’ and save it. Try opening the file again.
2] Use the Open and Repair feature in Excel
Hit the File tab and scroll down to the Open option. Select the Browse button and in the dialogue box that appears, choose the excel file that is showing the error message. Now, click the Open drop-down button and select the Open and Repair option from the list. Your Excel file will be checked for any damage or corruption and fixed immediately.
3] Change group permissions
Right-click the Excel file that you cannot open and select Properties. When the Properties dialog shows up, switch to the Security tab.
Hit the Edit button to change permissions. Once the file’s Permissions dialog opens, find and click the Add button. The action, when confirmed will open a new Select Users or Groups dialog box. Under it, locate the Advanced button. Thereafter, click Find Now to display all users and groups.
Choose Everyone from the list, and then click OK. Click OK again. Now, when you go back to the Permissions dialog, you’ll notice that the Everyone group has been attached to the user list. Select the Everyone group, check all the boxes under Allow, and then, hit the Apply button to apply the changes. Hereafter, you should be able to open the Excel file without any problems.
