Error when running program

What does this error mean? I get this when I try to run my program. It compiles fine but I can't find the problem because I have no idea what it means.

terminate called after throwing an instance of 'std::logic_error'
what(): basic_string::_S_construct NULL not valid
Aborted (core dumped)
Did you try to assign NULL value to std::string ?
Topic archived. No new replies allowed.