*This is the one you want*, NOT the one which is already there when you first click Default.

You'll see another Canon printer appear on the list, with a string of numbers after its name.

Click '+' to add a new printer, select Default in the top, left corner of the Add Printer window, then wait for 15-30 seconds.

Install the basic installation/networking software first, then update the drivers.

Yes, you will need to download at least these two items, since the drivers in the original installation will not be the latest & greatest.

Download the latest printer driver for your model, same link as above.

Download the basic Mac installation software for your Canon model at this link, *making sure that you're installing the Canon Networking software* (it may be a separate canon networking software link, or it could be bundled into their basic install - YMMV):.

Delete any previously installed (i.e., non-working) printers for the Canon.

The prerequisite for the steps below is that _your Canon is powered up, configured, & WiFi connected to your LAN_.

So, I wanted to lay it out in explicit detail here, error code 306 in the hopes that others could solve their problem quickly & easily.

Then, I found two different posts which said similar things (one which was really close by Pahu, thank you!) that led me to the correct result. Support Code : 306 A Communication Error Has Occurred. d.ecay Level 1 (0 points) Q: Error 306, using WiFi, often on the Canon PIXMA models I've seen the following Canon Printer Communication Error MacĮrror on numerous other boards and here on older Apple posts, too:Error Number 306 support code 306 canon printer A communication error has occurredI thought that I had done all the correct steps to solve the problem, but it still wouldn't work.

Canon mp610 printer error has occurred