linker command failed with: ld: file not found

Question

ld: file not found .../Library/Developer/Xcode/DerivedData/.../Universal.app/Universal

clang: error: linker command failed with exit code 1 (use -v to see invocation)

Can you help with this error?

Answer 1

Try to hit CMD-Alt-K or select Product -> Clean.

Answer 2

I localize this error with simple mistake:

in my project i have 3 files: main.m, SimpleClass.h, SimpleClass.m;

in file main, I have written:

#import <Foundation/Foundation.h>
#import "SimpleClass.h"
#import "SimpleClass.m" //Mistake

When I erased the third line, all had built success.