I've had this printer for years and I've never been able to print anything right. This is so frustrating. I've taken another attempt at figuring it out. After replacing all the inks (even though they were barely used) it is now complaining about paper size. As far as I can tell 11 blinks = wrong paper size.
I've selected A3, my paper size is 11" x 17" and put it into the top tray. I've selected A3 from Mac photo preview app. I've also tried printing from photoshop but I end up at the same paper size dialog. I am putting the paper in top tray so the long side is sticking up vertically, as it looks like the only way it could fit. I'm running out of ideas. I'm so frustrated with this printer.
Paper size options available:
Update After the comment below I've edited the "custom sizes" section and added 11x17. It seems to be printing now. Thank you.. I will post my progress