Just fixed this paper source is invalid problem today. When I get a Windows Update this happens to my Epson WF-2630. Here is what fixed it. Scan a document, go to your computer. Find it in the documents, (mine came up as a photo) Bring up the app. when I tried to print the photo it said at the top “let Windows Manage the apps”. I changed it to OFF. Then it gave me the option to change the type of paper and my printer worked again and to even make copies. So pick an app in the computer to print and you’ll find how to change the paper source!!