Hi there Bill! My name is***** am a computer professional with over 15 years of experience with both Mac and Windows. I'm sorry that you're having this issue. It would be my pleasure to help you resolve this. Is this a Canon Pixma Pro 10? If so, please click this link.
If you go there on your MAC laptop it should automatically recognize your operating system and direct you the correct driver, bt just in case it doesn't, click on the drop down arrow next to "OPERATING SYSTEM" and scroll down until you see and can select OSX El Capitan. After selecting in the list, click on the SELECT button, then on the next page scroll down and click the DOWNLOAD button. I do recommend that you uninstall the current printer driver before installing the new one. IF this does not resolve your issue please uninstall all software and drivers for the printer, then repeat the download process, this time being sure to click on the Software tab and the firmware tab, to redownload the applicable software and to check for firmware updates that the printer may need.
Please give this a try and let me know how it works for you. If this solves the problem., would you mind taking a moment to rate my service? I'd really appreciate it! Without a rating I am not credited for my answer. If you need more help, please let me know so I can continue to assist you.