title: Xcode won't run app on simulator
body: <p>Yesterday I uninstalled my App Store install of XCode and installed it manually from the Apple developer site.</p>
  
  <p>I had 9.4.1 and downloaded 9.3</p>
  
  <p>Ever since I've not been able to run any apps on the simulator.</p>
  
  <p>I see the following error in xcode:</p>
  
  <p><a href="https://i.stack.imgur.com/DZj1v.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DZj1v.png" alt="Xcode error message"></a></p>
  
  <p>I see this error in the Xcode logs:</p>
  
  <pre><code>iOSSimulator: 56E6A4AD-4D6F-4CB4-A666-E1DE0D49B101: Failed to launch app with identifier: com.mikevelu.Test and options: {
  
  "activate_suspended" = 0;
  
  arguments =     (
  
  );
  
  environment =     {
  
      "DYLD_FRAMEWORK_PATH" = "/Users/mikemurray/Library/Developer/Xcode/DerivedData/Test-fqvnwaelkrhrooepamzxmakiidkf/Build/Products/Debug-iphonesimulator";
  
      "DYLD_INSERT_LIBRARIES" = "/Applications/Xcode9.4.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libBacktraceRecording.dylib:/Applications/Xcode9.4.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libMainThreadChecker.dylib:/Applications/Xcode9.4.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/Develope&lt;…&gt;
  </code></pre>
  
  <p>and I see this error in the simulator logs:</p>
  
  <pre><code>(UIKitApplication:com.mikevelu.Test[0xf61e][2808][2983]): Service could not initialize: 99Z999: xpcproxy_sim + 9282 [1524][AF02A7E2-099C-3F21-AB91-5AA7DB3FFA58]: 0x5
  </code></pre>
  
  <p>I've tried the usual culprits, removing derived data/cleaning build folder/restarting simulator/restarting xcode/restarting macbook.</p>
  
  <p>I've also tried completely uninstalling xcode and reinstalling (uninstalled 9.3 and tried installing 9.4.1), doesn't seem to make any difference.</p>
  
  <p>Seen a few similar questions posted and one of the most common fixes seems to be removing any checked blank environment variables in the scheme, I can't find any to remove. I've tried running both in debug and release, I've tried disabling Debug executable and selecting the executable on launch. Also tried deleting the scheme and creating a new one.</p>
  
  <p>Also set verbose logging on the simulator and I didn't get any more illuminating information.</p>
  
  <p>If if install the app manually using simctl and launch it using simctl it will launch without complaints (that's what prompted me to try disabling debug executable).</p>
  
  <p>I see this issue regardless of which project/workspace I have open in Xcode, the example I'm using currently is just a blank project I created to try and get to the bottom of the issue.</p>
  
  <p>I'm edging closer and closer to a complete restore being the most logical next step, but I'd like to avoid that if possible.</p>