Hi, All Sorry to bother you with this. I met a problem with the Random library in the latest release v1.47. The following code works well for v1.46.1: double unirand_real(double a, double b) { // Create a random number generator engine static boost:: mt19937 rng_real(static_cast<unsigned int>(std::time(0))); // select Uniform probability distribution boost::uniform_real<double> dist(a, b); // bind random number generator to distribution, forming a function boost:: variate_generator < boost:: mt19937 &, boost::uniform_real<double> > sampler(rng_real, dist); // sample from the distribution return sampler(); } However, when I adopted my code to v1.47, the following code failed due to memory access violation after a number of function calls: double unirand_real(double a, double b) { // Create a random number generator engine static boost::random::mt19937 rng_real(static_cast<unsigned int>(std::time(0))); // select Uniform probability distribution boost::random::uniform_real_distribution<> dist(a, b); // return random sample return dist(rng_real); } I will appreciate your help with this problem as right now I think the Random library may have a bug. Best, Jacky