Constant crashing while on World Map Builder

Hi, I am currently working on a world map based on Japan around the Edo time period. I managed to create a City and a few POIs within it, 1 Ocean and 1 Forest. Now I wanted to add a secret ninja village into the forest, but the Map builder keeps crashing over and over again when I try to move the village to the Forest Area. I also can*t really save my progress thanks to that.

Another question I have: Is there a limit on how many areas and POIs I can create on a map for a Campaign start?