after hplip 3.15.2 upgrade printer not found

I have a Dell Desktop and a Sony laptop, both running Ubuntu 14.04. A couple of months ago, I bought an HP Officejet Pro 8610, to replace an older Officejet which had stopped scanning. I got it set up (hplip 3.14.10), with some effort, and was able to print from both computers. Today, on the desktop I was offered an upgrade to hplip 3.15.2, and like a good boy accepted this (much to my sorrow) with all the default settings. The printer is connected via wireless only. After the installation, the printer status is "Stopped - unplugged or turned off". hp-check returns code 12 for both the printer and the fax (apparently two devices according to hplip). No combination of turning off the computer and the printer resolves this "stopped" condition. The printer is found just fine during the setup process, and the printer itself is happy with its wireless settings. No combination of turning off the computer and the printer resolves this.

Meanwhile, I can print from the laptop (hplip 3..14.10, not upgraded) just fine, and the printer status is "idle."

I uninstalled hplip 3.15.2 from the desktop per the instructions from HP, then installed hplip 3.14.10 as I still had the files. This all went fine, apparently, but the result is the same - the printer is still stopped on the desktop, and of course, I can't print from the desktop. I can still print from the laptop.

Any suggestions would be appreciated - I am completely puzzled.