This is a quick guide for the problems, however the result varies.
Editor (Maps,Scenario,Civilization,Etc):
For Android users, when you join the game you can see the editor option
Click in and you will see this
From here you will choose the option depending on your need, for example you want to create new terrain/unions etc, go to game editor and you will see more options.
Feel free to explore those options!
Game Crashing:
I have rarely face such problems, however if your game keeps crashing, you might want to clear all the game data, then uninstall the game