My guess is that it has to do with the particles. You keep adding them to your domain and they aren't finding the exit. You are also using a student license near the max cell limit. Maybe there is a limit to how much memory allocation is allowed with the student version and with the mesh and particles you exceed it. This is not definite, maybe an ANSYS Support can answer here.

Do you have access to an Research license? Maybe try it there where you don't have these restrictions. 

One more (lesser) possiblity, it could be the adaptive timstep. Try using a fixed value.