Lightroom 6.4 (on PC Windows 10) has been extremely troublesome with our 2 DS40 printers.
We are a tourist attraction sending in tours and taking 6-10 photos of the people on those tours, automatically importing to Lightroom 6.4, selecting all 6-10 photos on that tour and printing them all, every 10 minutes through the day.
80% of the time at least one of the 2 x DS40 printers works fine.
We have determined the problem is not from Windows or the Printers, but coming from Lightroom. We've run Lightroom 4 for years with no printer problems and recently upgraded to 6. Can we roll back to 4 or 5? Or does anyone have a fix for the printer issue?
You could reinstall and use Lightroom 4, but Lightroom 5 requires a separate license that is no longer sold by Adobe. It would be necessary for you to find Lightroom 5 from a reseller such as Amazon or B & H Photo, etc. Also, be aware that any catalogs that you have created using Lightroom 6 will not be compatible with previous versions of Lightroom.