I have installed Kudan 1.1.3 in Unity 5.3.4. I have followed 100% accurately the scene setup from Kudan's "getting started" guide. I hit "build and run", everything looks OK but once starting on Nexus 9, the app dies immediately. I generated a bug report with ADB and here is the crash narrowed to whatever seemed to me relevant :
05-24 13:38:28.619 5751 5777 E Unity : [KudanAR] Graphics vendor: NVIDIA Corporation
05-24 13:38:28.619 5751 5777 E Unity :
05-24 13:38:28.619 5751 5777 E Unity : (Filename: ./artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 37)
05-24 13:38:28.619 5751 5777 E Unity :
05-24 13:38:28.620 5751 5777 E Unity : [KudanAR] Graphics version: OpenGL ES 3.1 NVIDIA 343.00
05-24 13:38:28.620 5751 5777 E Unity :
05-24 13:38:28.620 5751 5777 E Unity : (Filename: ./artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 37)
05-24 13:38:28.620 5751 5777 E Unity :
05-24 13:38:28.667 617 794 D ConnectivityService: notifyType CAP_CHANGED for NetworkAgentInfo [WIFI () - 100]
05-24 13:38:28.719 5751 5777 D Kudan : KudanAR initialise called
05-24 13:38:28.721 5751 5777 D Kudan : CameraPreviewAndRender initialise called
05-24 13:38:28.722 5751 5777 D Kudan : OpenGL ES version is set to: 3
05-24 13:38:28.722 5751 5777 D Kudan : OpenGL ES Can use glBindArray: true
05-24 13:38:28.722 5751 5777 D Kudan : CameraPreviewAndRender loadShaders called
05-24 13:38:28.722 5751 5777 D Kudan : CameraPreviewAndRender CreateTexture called
05-24 13:38:28.723 5751 5777 D Kudan : CameraPreviewAndRender BindSinkTexture called
05-24 13:38:28.723 5751 5777 D Kudan : CameraPreviewAndRender CreateShaderProgram called
05-24 13:38:28.752 5751 5777 D Kudan : CameraPreviewAndRender SetupShaderProgram called
05-24 13:38:28.752 5751 5777 D Kudan : CameraPreviewAndRender CreateQuadGeometry called
05-24 13:38:28.752 5751 5777 D Kudan : StopTrackerThread called - bWaitForFinish: true
05-24 13:38:28.752 5751 5777 D Kudan : StartTrackerThread: creating thread TrackerThread1464111508
05-24 13:38:28.754 5751 5777 D Kudan : StartTrackerThread: Finished
05-24 13:38:28.767 5751 5777 I kudan-ndk: checking
05-24 13:38:28.782 5751 5751 F libc : Fatal signal 11 (SIGSEGV), code 1, fault addr 0x0 in tid 5751 (eu.kudan.ar)
05-24 13:38:28.831 617 981 I WindowState: WIN DEATH: Window{a426155 u0 SurfaceView}
05-24 13:38:28.832 617 654 I chatty : uid=1000(system) InputDispatcher expire 2 lines
05-24 13:38:28.834 617 979 I WindowState: WIN DEATH: Window{4004c13 u0 eu.kudan.ar/com.unity3d.player.UnityPlayerActivity}
05-24 13:38:28.834 617 979 I chatty : uid=1000(system) Binder_7 expire 1 line
05-24 13:38:28.847 617 984 I ActivityManager: Process eu.kudan.ar (pid 5751) has died
Everything looks OK until the "kudan-ndk: checking" line. I am not a pro using Android but I did considered the "Gotchas" at the bottom of this turotial page : https://wiki.kudan.eu/Unity
I have installed Android API 22 using Android SDK manager since that level is stated as the targeted one. I have also forced screen orientation to be "landscape left" in player settings in Unity and I have even installed Android API 23 since my Nexus 9 has Android version 6.0.1. Maybe that last part is causing the problem... or not? Can anyone share a better understanding of this problem?
We have put new tutorials on the Kudan Wiki that should be much easier to follow. The ones helpful to you are called:
My First Augmented Reality App (1.1.3 Stable)
Building the App - Android
In response to your actual question, crash on start is generally caused by an incorrect API Key, which is set on the Kudan Camera. Ensure that this matches with its according Bundle ID, which is set in the player settings in Unity.