title: Terminating app due to uncaught exception 'NSInvalidArgumentException' - unrecognized selector
body: <p><em><strong>I'm trying to make a simple notes app. When I run the project, in the debug area, it says</em></strong>; </p>
  
  <pre><code>[1752:19d03] -[TableViewController createEditableCopyOfDatabasteIfNeeded]: unrecognized selector sent to instance 0xa147d20
  
  [1752:19d03] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[TableViewController createEditableCopyOfDatabasteIfNeeded]: unrecognized selector sent to instance 0xa147d20'
  </code></pre>
  
  <p><strong>And my code, includes <em>createEditableCopyOfDatabasteIfNeeded</em>, is</strong> ;</p>
  
  <pre><code>- (void)createEditableCopyOfDatabaseIfNeeded {
  
      NSFileManager *fileManager = [NSFileManager defaultManager];
      NSString *documentDirectory = [self applicationDocumentsDirectory];
      NSString *writableDBPath = [documentDirectory stringByAppendingPathComponent:@"NotesList.plist"];
  
      BOOL dbexits = [fileManager fileExistsAtPath:writableDBPath];
      if (!dbexits) {
  
          NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"NotesList.plist"];
  
          NSError *error;
          BOOL success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&amp;error];
          if (!success) {
              NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]);
          }
      }
  }
  </code></pre>
  
  <p><strong>Where is the problem here ?</strong>
  <em><strong>It might be an easy one but I'm new to Xcode.</em></strong>
  <em>Thanks for help</em></p>