I’m using N-Track build 1846 with the Emu 1820m system. The solo and mute buttons for the tracks, both in the mixer strips and timeline do not work at all. Any ideas why? 
I have an 1820M too… you really need to get your mind around the PatchMix mixer and the endless routing assignments you can use. Do the Solo and Mute buttons not function correctly when playing back a recorded track or tracks? Depending on your routing, Mute and Solo WILL NOT function like their hardware counterparts on a console! With a default template for PatchMix, you are going to here your inputs direct BEFORE n-Track actually “sees” them. You can change that if you want. That’s why I suggested studying the 1820 manual and REALLY getting your head around PatchMix. It’s routing possibilities are extremely powerful and I admit, at times, confusing.
Now. Hit the books! 
TG
PS BTW, I love my EMU. I hope yours is a good experience.