How to fix SharePoint error "Cannot open the file.."

1.  Go to portal.office.com and sign in to your Microsoft account.

2.  Click the App Launcher and select SharePoint.

3.  In SharePoint, choose the Sites where your file is located.

4.  Select Documents and choose the file that is not opening by clicking on the circle symbol at the left side of the file name. Then, click Download.

5.  You can choose to browse your file location and click Save.

6.  Go to your File Explorer and search for the saved file.

7.  Select and right-click the file.

8.  Then, choose Open with and select the app to use to open the file. Check the option Always use this app to open. Click OK.

9.  Close the file and re-open it.