What do the error codes E1 and E2 mean on my HP Smart Tank 6000, and how do I fix them?

Error codes E1 and E2 indicate a paper size mismatch — E1 means the paper width doesn't match the print job, and E2 means the paper length doesn't match. To fix this, press the Cancel button, load paper that matches the size of your print job (or change the paper size settings in your application), and then print again. You can also change the paper size settings through the embedded web server (EWS). (Page 8)