Do you mean: "IDE returned 1 exit status"? If so, it's because there probably was an error in your program and it didn't return correctly at the end of it.
A program should always return 0 when terminating. If it's returning 1 at termination there was some kind of error interrupting.
Are there any other messages apart from that one?
Actually, this looks like a linker error, usually seems to be preceded by a message "undefined reference to xxxx" - that is the important message.