Process finished with exit code 3

[Ibon Goikoetxea]

Hi 

I am using or-tools for Python with Pycharm IDLE.

While running a graph-coloring problem, the solver crashes during the optimization phase, after having already found some solutions. 

The IDLE shows:

This application has requested the Runtime to terminate it in an unusual way.

Please contact the application's support team for more information.

Process finished with exit code 3

What does this exit code 3 mean? Any suggestion how i can check/debug where the solver crashes?

thanks