When I use omnishere instrument in my arrangement it randomly, without any warnings shuts my computer down. It happens only when I use omnisphere. But when I freeze this truck and mute omnisphere truck, then everything works fine. It comes completely unexpected, so sometimes I lose some material.
You also have to configure omnisphere to remember these settings in the future. Go to the utility menu / Midi learn and automation / and select "Ignore assignments when loading multi". Then these assignments will not be removed in the future.