_OBJ_CLASS_$_project name in iPhone

Greetings of the Day,

In my app i am trying to integrate slider which is done successfully but i am getting error

Undefined symbols:

"_OBJC_CLASS_$_project name", referenced from: objc-class-ref-to-project name in Detailed.o ld: symbol(s) not found collect2: ld returned 1 exit status

which is in NSObject.h:146 :

@interface N开发者_如何学CSObject (NSDiscardableContentProxy)

- (id)autoContentAccessingProxy NS_AVAILABLE(10_6, 4_0);

@end

i am not getting how rectify the issue.Please help me!!!

Thanks in Advance.

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Please remove file "Detailed.h/m" from your code if you drag/drop from other project direct and add them again.