google a solution for Mozilla: have fun yay ... found a fix !!! here's the process for future reference go to the firefox cofiguration by typing!.. "about: config" in the adress bar then right-click anywhere, and Go to "new -> string". for the preference name, type ... network.protocol-handler.app.rtsp for the value, Just Type in the path to the executable ... But in My Case, The EXE Cutable Was Located in "/ usr / local / bin", SO i Just Typed it's name ... HXPLAY NOW WHENVER I CLICK THE LINK, The Helix Player Pops Up and Plays Its it, instead of getting the error :) I'll Also Rename The Thread So it'll be easy for trouplanooters to find