Crashes with midi file / DSL music device

Hi Trying to do some work involving midi files and using DSL music device as the sound source. When I load the file so that each instrument has a separate track, and place an instance of DSL on each, Reaper crashes immediately when playback is attempted. I have not found Reaper crashy at all in the past. Anyone have any ideas about this? I am quite a noobie, so please assume a low knowledge level! Any input gratefully received ;0)

Not a Mac person, but is it necessary to have the plug on each individual track? Cant it do multis?

Thanks for your reply .. I did this from a tutorial on youtube, so I assume DSL is needed on each track when it is a multitrack performance, but not sure. There may be some routing method I dont know about. Anyway .. Im thinking it is a corrupted midifile, because I have done the same thing with another midifile, and no crashes .. fingers crossed

Or maybe not 

I spoke too soon .. now Reaper crashing with that file too.