If anyone wants to check, here is a video showing a Firefox dev. console (F12 key) and errors occured on https://www.openstreetmap.org/search?query=Oslo#map=8/59.973/10.723
I would like to find the causing extension without the need of disabling extensions randomly or by disabling half of extensions, then if issue solved, disable half of that half etc..
Sometimes it helps to hover over the link near the error on dev. console (F12 key), Console tab, to see the moz-extension://somestring and find first characters of the string at page about:debugging#/runtime/this-firefox
Though this time, it does not show that IMO (per the linked video).
If I should click something particular in a FF dev. console (F12), please guide me. Thank you.