Q: el capitan wont let me print on my ******* xp310

Greetings McDaveCallagain,

Thanks for using the Apple Support Communities!

I know that unexpected issues after a software upgrade can be very frustrating, but I want to assure you that we are here to help!

Based on your post, I did a search and think the printer you own and are having issues printing to is an Epson XP-310 Series. If this is correct, your printer should be able to both print and scan using OS X 10.11 El Capitan according to the following article. 

Printer and scanner software available for download for your Mac - Apple Support

Because you are having an issue printing to that printer, I would suggest reading over and working through the suggested steps in the attached article. 

OS X El Capitan: Printing troubleshooting

Cheers!