I downloaded Marts Mutant Mod today but when i installed it every time I would start up the game it would crash. My game works fine when the mod isn't installed (I tested it). Can someone help?

Sounds like a missing master, or something else that went wrong during install.
Can you post your load order?

If the game crashes when you open it, it probably just means the load order is wrong. Post your load order so we can help.