I had a similar problem when first running Crescendo v 3.00. I use Win 7 Pro 64b and had an old version of Coolsoft VirtualMIDISynth
as my default midi sound font handler. When I upgraded it to rev 2.3.0 more than one midi application could
play my midi files, including Crescendo. Sound font I use with it is: "FluidR3_GMfont.SF2"