The problem was residency. I compared my printed return to my wife’s. Hers was blank in the current (changed) residence box. Mine had the same province as the previous residence. In the real world that’s the same as not moving, but the software didn't think so. Once I cleared the new residence, mine netfiled.
It was frustrating that the error was- "it’s one of these 20-362 things, good luck figuring it out", and not - "you can’t netfile because you said you moved." It was also frustrating that I couldn't just ask the software, what's different between these two?