Q. In SharePoint, I keep getting an error when I import Excel workbooks. Why does it say it’s not a valid Excel File?
A. It’s frustrating to get an error message that doesn’t help you solve the problem. Sometimes when you import an Excel worksheet as a list in SharePoint you get this message: “The specified file is not a valid spreadsheet or contains no data to import.”
The actual problem at hand is that your SharePoint site is not among your Trusted Sites in Internet Explorer. To fix this, navigate to your SharePoint site. Click on the Options icon (gear) or click on Tools. In either case, choose Internet Options, then the Security tab. Then choose Trusted Sites and the Add button. Your SharePoint URL should be showing in the Add this website … field.
Try your import again. It should work. Occasionally, the problem continues because some columns in your work sheet contain rich content, which may not translate well to SharePoint.