Forcite simulation process is stuck at some point with no warning, when I apply multi-cores to MS7.0

Dear all,

I have encountered a weird issue recently with Material studios 7.0 on simulating normal cases with multi-cores. It seems that the process can only persist for a certain time, maybe for 3-5 hours, when I choose to apply more than one single core to the Forcite module. When it reach the maximum time, the MS will do nothing on the simulation, the CPU usage will fall down like there's nothing in computing and the progress will stop at that number it stopped. No warnings or errors are popping out. However, it works fine when I use single core with all sorts of simulations (as you know, this requires a large amount of waiting time).  

Does anyone know how this come and how to resolve this issues? I tried reinstall the MS, systems restoring and many other methods, this problem is still there. I am pretty sure that this computer worked fine half year ago and the tests showed that the CPU is in good condition now.

Thanks for the help from anyone!