Recently a user reported an issue with SharePoint Links list in Mozilla Firefox. When we try to open a link to a local file (file:///x:/folder1/folder2/filname.ext), nothing happens.
This is a known security restriction (bug?) with links to local files in Firefox and not just related to SharePoint. The known issues documentation form Mozilla says,
user_pref("security.checkloaduri", false); (Bug 84128)”
Looks like they haven’t fixed this issue yet. You can find the security error message by opening Tools > Error Console (Ctrl+Shift+J) in Firefox. You can find the Mozilla documentation here.
There are some workarounds for this limitation buth those are fixes for browser and client computer, not for server. More details can be found here.