Soundfont doesn't transfer to MuseScore.org

I used a soundfont by GeneralUser because the default Saxophone sounds awful in MuseScore 2.0. I worked on my song and it sounds nearly perfect (drums give me dificulty anyway). When I uploaded it to MuseScore.org, it reverted back to the default of terrible Sax, the synthesizer (instrument) reverted, for some reason, to Yamaha grand sound and the drum set line was making piano noises instead of Drum noises. Whats going on?