On Linux, Minecrafts communication with the system is broken since the first day. it opens system pathes with firefox, tries to open webpages with firefox, even when something other is standard browser, it tries to install firefox (via appstore), when its not installed.

i dont know what you use but for all this you should try to call
xdg-open <URL|FILE>
xdg-open is the freedesktop standard. it will use the standard app for this type or will open the webpage with the standard browser on all desktops.