@egezort(View Post) What is this fatal error? What are you trying to do, add an element? Compile a clean source etc. Take me through what you have done so far, and what the error is.
"Fatal Error" just means it can't compile for whatever reason. This is an example of some output you may see.
src/elements/xeno-xeno.c: In function 'update_XENO': src/elements/xeno-xeno.c:20: error: expected ')' before '{' token src/elements/xeno-xeno.c:33: error: expected expression before '}' token
Blue Bold is the file with the error, red underline is the line numbers you need to look at. For this one I just removed a ) at the end of an if statement. Putting it back solves both problems.
If you give us the full error you get and the file on pastebin we can look at it for you.