Seems like after gathering too much hour (since sometimes i forgot to turn off the PC and game), my game stops working. It froze when there's an event, whether its transformation or other event.
It does sounds like the game run out of memory. It can happen with rpg maker games if you let them run for hours on end without a break. The best thing to do is to save and close the game if you playing more than 4 to 8 hours.