I saw you tried different versions on 2 different machines -- it certainly suggests something related to your setup: I can zoom, open in new tab, save as, etc o

I saw you tried different versions on 2 different machines -- it certainly suggests something related to your setup: I can zoom, open in new tab, save as, etc on Firefox 41 on Ubuntu 14.04. Do you have running app for mouse gestures? That's the only thing I can think of that makes sense in your scenario. Try holding the right click for a few seconds, see if the context menu appears.