title: Undefined symbol: _OBJC_CLASS_$_WKInterfaceController error after updating Xcode to version 11.1
body: <p>I updated Xcode to version 11.1 and got this expected error:</p>
  
  <blockquote>
    <p>WatchKit is not available when building for iOS Simulator.</p>
  </blockquote>
  
  <p>Then I deleted WatchKit from iOS app target as suggested. Since then I am having this error:</p>
  
  <blockquote>
    <p>Undefined symbols for architecture x86_64:<br>
    "_OBJC_CLASS_$_WKInterfaceController", referenced from:
          objc-class-ref in INFOnlineLibrary(IOLWatchKitHelper.o) ld: symbol(s) not found for architecture x86_64 clang: error: linker
    command failed with exit code 1 (use -v to see invocation)</p>
    
    <p>Undefined symbol: _OBJC_CLASS_$_WKInterfaceController</p>
  </blockquote>
  
  <p>PS: The x86_64 part is dependent on the device/simulator choice. If I choose a real device it gives the same error for arm64. So I don't think it is a architecture issue also because of the fact that the framework that includes  WKInterfaceController is just a standart watchOS framework which is Watchkit.</p>
  
  <p>PS_2: There is no use of WKInterfaceController or even WatchKit in the iOS app. It is only used in WatchAppExtension part</p>
  
  <p>What I have tried so far:</p>
  
  <ul>
  <li>First thing was to add WatchKit framework to WatchApp and
  WatchAppExtension targets.</li>
  <li>When I searched for <em>Undefined symbols for architecture x86_64</em> type of errors in general there were many different suggestions. Even though I think it is not architecture dependent thing, I tried setting building active architecture only no in all targets. The most suggested putting $(inherited) to the search paths was already done before.</li>
  <li>Checked the target of .m files. They are all fine.</li>
  <li>I even went far and commented all the code that is using WKInterfaceController. Nothing has changed after. I also deleted watch app, it still looked for _OBJC_CLASS_$_WKInterfaceController but I am not sure did it properly.</li>
  <li>I checked the WatchKit.framework Device Supporting Files with <code>file WatchKit.framework</code> command and saw that it supports arm64. Then added that library manually to libraries, ran on device but still didn't work.</li>
  </ul>