Mac version of AccuRIP cannot find printer when choosing connection local (USB) in AccuRIP Setup. If the OS can see the printer then so can AccuRIP. Check all printer connections, USB ports and cables.
Using the Apple System Profiler see if the printer is listed as a USB device. If not then the issue is a bad connection. You can access the Apple Profiler by choosing from the Apple Menu “About This Mac” the click on “More Info” and from the “hardware” list chose USB to show all connected USB devices. If your printer is NOT on the list then AccuRIP cannot connect to it.
Once the profiler can see the printer so will AccuRIP.