guys i know this is a little late but i was facing this issue for a while i wanted to disable some settings but it was creating some problems so to really get to the bottom i tried some things , if you are on firefox as i am mainly testing things on it , the most easiest way to really stop those type errors when running on localhost as dev just diable the react developer tools errors are coming from enablin that extension i will be doing some more digging but for now this is the eaisest and most forward way to stop those errors there is nothing wrong with the nextjs project template or configs these two just aren't working together..if some have more suggestions please feel free to write below