error code 300

One day last week my MacBook couldn't communicate with my Canon printer that has always worked like a charm. The recent High Sierra upgrade seemed to be the issue. So I thought I would reinstall an older version of the OS....not the best idea I ever had...after spending an afternoon talking to an Apple support tech...I had a completely crashed hard drive showing only a white circle with a line through it.....after many trials and tribulations, I had to take it to a Mac repair person who re-installed the El Capitan hard drive...and recovered much of my drive except for recent applications like Pages, KeyNote, Numbers.....

I managed to find a way around that on my own again...but sadly no printer access although I had re installed the drivers multiple times. So I tried to print on someone else's printer at their place...no problems encountered. But when I brought that printer home to check this out further....it wouldn't communicate with my computer....back to square one. FINALLY, A BRAIN WAVE....maybe this was a WIFI issue and not my equipment at all.....so, I did a reboot of my BELL 3000 WIFI router....and wouldn't you know, everything is working as though it had never happened. It has cost me 150$,too much time and a h...of a lot of anxiety since I need this equipment to work.

In this forum, I tried many of the suggestions but found that there are no real solutions to this error problem....but believe me when I say that this one actually worked........as it often is with technology, one tends to overthink it...