I recently upgraded to NX 11, and I'm getting a reoccurring fatal error when I'm in the simulation environment. I was just putting various loads and constraints, took a break, then came back to a fatal error "Fatal error detected unable to continue Unhandled operating system exception: c000000d"
I'm running NX on a Surface Book with an i7 processor and an Intel(R) HD Graphics 520 chip
Have you installed any maintenance releases or maintenance packs? If not, I'd try that if you're able to. You also might get more specialized help (for simulation) in the Simcenter area rather than NX Design.