Fred, it may be possible that Canon just hasn't released new versions of their printer driver, scanner driver and Canon Utilities for your particular model. Unlike you, I in fact met with success in getting my Canon printer working with Mojave earlier today. Here is my story, if you are interested in reading it:
I don't print all that often, but today I had to copy and print some documents for an important meeting I was to have tomorrow. One document in particular had to be printed from my 2017 27" 5K iMac running Mojave 10.14.3, being as I didn't have a hard copy on hand to make a copy from.
My printer is a Canon PIXMA MG7720. The printer itself continues to work fine, but as soon as I tried to print that one document from my iMac instead of manually placing it in the printer, I hit a brick wall. My first problem was that the job window insisted that my printer was not even connected to my network. So I fiddled with it a bit trying to connect it via my Wi-Fi network, and then via an ethernet cable. I finally managed a connection via Wi-Fi.
But, oh gosh, that wasn't the end of my fight just yet. I repeatedly tried to print the document, but the printing queue window kept saying that it couldn't open the "PPD" file. If you are not familiar with the term, it means "Postscript Printer Description" file.
That is when a light went off in my head. Even though I already had the Apple Canon Printer Drivers 3.4 from last December installed on my iMac, given how many printing issues some people have been having with Mojave, it occurred to me that Canon might have some newer drivers on their website. So I paid them a visit.
Sure enough, I found package installers for a newer printer driver, a newer scanner driver, and newer versions of all of the other utilities which make up the Canon Utilities package. So, I downloaded everything and installed them. It was seven downloads in all. After that, I rebooted my iMac. I reopened my document in the "Preview" app, and then clicked on the "Print" option under the "File" menu. To my great relief, the document printed without a problem.
So, keep looking my friend. If this is what your problem is, Canon is bound to release new drivers for your machine soon. I hope that you found the above helpful. Please let me know, okay? Thanks!
