Erm...assertions are just conditional statements (if/else) that crash the program if the condition is true. Assuming your code works fine in real life, I would defer you to this thread (
https://groups.google.com/forum/?fro.../czsuczmquts); It seems to be an error in ODE (which is a C++ graphics library). The LabVIEW simulator was written in C++, using the ODE physics libraries.
Maybe try using the absolute simplest models in your program, and seeing if the problem still persists?