title: Undefined symbols for architecture i386:"_OBJC_CLASS_$_TLFApplicationHelper"
body: <p>I'm working on xCode 6.3. I attached external library on my application. I researched this issue so long. I tried whole solutions. But they didn't help. Changing scheme name, removing paths, adding/removing architectures...I got this error: </p>
  
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  <pre class="snippet-code-html lang-html prettyprint-override"><code>Undefined symbols for architecture i386:
    "_OBJC_CLASS_$_TLFApplicationHelper", referenced from:
        objc-class-ref in AppDelegate.o
    "_OBJC_CLASS_$_TLFCustomEvent", referenced from:
        objc-class-ref in AppDelegate.o
  ld: symbol(s) not found for architecture i386
  clang: error: linker command failed with exit code 1 (use -v to see invocation)</code></pre>
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  <p>My settings:</p>
  
  <p>Valid architecture: armv7 armv7s arm64
  Architectures: armv7 arm64
  Build Active Architecture : No</p>
  
  <p>By the way, there is no TLFApplicationHelper.m and TLFCustomEvent.m. They are TLFCustomEvent.h and TLFApplicationHelper.h.</p>
  
  <p>When I set Build Active Architecture Only as No, error messages are like that:</p>
  
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  <pre class="snippet-code-html lang-html prettyprint-override"><code>Undefined symbols for architecture x86_64:
    "_OBJC_CLASS_$_TLFApplicationHelper", referenced from:
        objc-class-ref in AppDelegate.o
    "_OBJC_CLASS_$_TLFCustomEvent", referenced from:
        objc-class-ref in AppDelegate.o
  ld: symbol(s) not found for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)</code></pre>
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