

But if you try to load a local resource as localhost in Firefox…
For the sake of completeness:
Firefox contains a security patch which restricts the kinds of files that pages can load (and methods of loading) when you open them from a file:// URL. This change was made to prevent exfiltration of valuable data within reach of a local page, as demonstrated in an available exploit.
More info: https://developer.mozilla.org/docs/Web/HTTP/CORS/Errors/CORSRequestNotHttp
Insecure, but fast fix, if you don’t want to install a local webserver:
about:config
security.fileuri.strict_origin_policy
change to false
Was a big fan of Secret of Mana (1 and 2), Secret of Evermore and different Zelda games. I tried to force me into playing FF, because it looked promising, but I can’t stand the role-play battle mechanics.