I appreciate this is part of your extensions, but I see this message in all sorts of places these days, and I hate it: how I fixed it (EDIT: this fix seems to massively speed up the browser too) was by adding a dead file
physically create the file it wants\ where it wants, as a blank file (EG: "popper.min.js.map
")
put this in the blank file
{
"version": 1,
"mappings": "",
"sources": [],
"names": [],
"file": "popper.min.js"
}
make sure that "file": "*******"
in the content of the blank file MATCHES the name of your file ******.map
(minus the word ".map")
(EDIT: I suspect you could physically add this dead file method to the addon yourself)