Firefox' standard option how to open .m3u files is Quicktime Player. But Firefox is then throwing an error window that says that Quicktime Player cannot play .m3u files. Well, that is only partially correct. If opened as a file it won't work, but when copied the URL of that file and opened it directly in Quicktime Player as a "location" It would play just fine. So why cannot tell Firefox to Quicktime Player to open a .m3u file as a location and not as a .mp4 file?
As a matter of fact the problem that I am experiencing is actually a .m3u8 location.