Out of the blue and after 3 years with my Canon Pixma Pro-100 I am unable to print photos or anything else. I am unable to add this printer. I tried resetting the printer to no avail and also downloading new drivers. Still no printers can be added. Using Mojave and my OS is updated.I also have an Epson printer which was giving me the same exact problems but am able to add it now but have no idea why.