title: Unity + ARCORE DllNotFoundException: arcore_unity_api
body: <p>I tried to run the arcore samples for unity as described on the following page: <a href="https://developers.google.com/ar/develop/unity/quickstart-android" rel="nofollow noreferrer">https://developers.google.com/ar/develop/unity/quickstart-android</a></p>
  
  <p>But it doesn't work. The app starts and it is searching for the planes, but the camera feed is black. In the logcat there is the following exception:</p>
  
  <pre><code>DllNotFoundException: arcore_unity_api
      at (wrapper managed-to-native) GoogleARCoreInternal.ARPrestoCallbackManager/ExternApi:ArCoreUnity_setArPrestoInitialized (GoogleARCoreInternal.ARPrestoCallbackManager/EarlyUpdateCallback)
    at GoogleARCoreInternal.ARPrestoCallbackManager.InitializeIfNeeded () [0x00000] in &lt;filename unknown&gt;:0 
    at GoogleARCoreInternal.ARCoreAndroidLifecycleManager.CreateSession (GoogleARCore.ARCoreSession sessionComponent) [0x00000] in &lt;filename unknown&gt;:0 
    at GoogleARCore.ARCoreSession.Start () [0x00000] in &lt;filename unknown&gt;:0
  </code></pre>
  
  <p>I also tried the plain android samples, which work fine. What could be the issue that it doesn't work with unity?</p>