title: No visible @interface for
body: <p>I have gotten this error on several occasions and am unclear as to what causes the error in general. After looking for over an hour on stack overflow and google I still don't have an answer. Could someone help? </p>
  
  <p>I've seen several specific answers but nothing that says why the error happens, only "do x", or "do y".</p>
  
  <p>I haven't included code yet because I want to know the reason that this error happens in general so I can fix my code in the future whenever I get this error.</p>