Welcome to the forums Albert0345, please excuse the standard answer but you need to give some more information before anyone can help please answer:
What game are you modding? (RTW or BI) Which patch version? (eg 1.2 or 1.5)
Are you modding a released mod that you have downloaded? If so please state which.
Confirm that you have -show_err on your shortcut and state if it is giving a message or not.
If you are getting a message please quote it.

Also explain in detail the nature of your crash / problem. For campaign map problems that can be;
KTM = Kick-Back to Menu, you try and load campaign but get sent back to previous menu instead.
CTD = Crash to Desktop, if that is what you get please state what screen / stage of loading bar you where in when it crashed.
Other = loads map but with distorted graphics, loads map but crashes on scrolling.
If you haven't got -show_err on shortcut yet see here