Log in or register to post comments

black screen on 2nd time loading app

May 27, 2015 - 7:54pm #1

Hi there,


I'm using the vuforia playback sample version 4.2.3, in xcode 6.2 for iOS. I haven't modified the sample in any way, yet I'm getting a black screen upon pressing "start" in the sample. The strange thing is this only happens after an initial build. On the initial build the sample seems to work just fine. When ran a second time, or subsequently, I get the black screen of death. This only happens on the rear camera, if I switch to the front, the camera works. I've been looking through the forums and a lot of things seem Unity related but this is the straight up example. Any ideas what could be causing this? Here is the Log from Xcode in case it helps.


2015-05-27 22:48:36.352 VidPlayback[2108:60b] debug: shaderName=(Simple), shaderFileTYpe=(vertsh)

2015-05-27 22:48:36.360 VidPlayback[2108:60b] debug: shaderPath=(/var/mobile/Applications/121AF21D-6B4C-42A0-9FC0-47BE1FD210E9/VidPlayback.app/Simple.vertsh)

2015-05-27 22:48:36.366 VidPlayback[2108:60b] debug: shaderName=(Simple), shaderFileTYpe=(fragsh)

2015-05-27 22:48:36.371 VidPlayback[2108:60b] debug: shaderPath=(/var/mobile/Applications/121AF21D-6B4C-42A0-9FC0-47BE1FD210E9/VidPlayback.app/Simple.fragsh)

2015-05-27 22:48:36.640 VidPlayback[2108:6c03] INFO/AR(2108) 2015-05-27 22:48:36: QCAR SDK version 4.2.3

2015-05-27 22:48:37.383 VidPlayback[2108:60b] AVPlayerItemStatusObservationContext -> AVPlayerItemStatusReadyToPlay

2015-05-27 22:48:37.434 VidPlayback[2108:60b] AVPlayerItemStatusObservationContext -> AVPlayerItemStatusReadyToPlay

2015-05-27 22:48:37.876 VidPlayback[2108:b203] loadAndActivateImageTrackerDataSet (StonesAndChips.xml)

2015-05-27 22:48:37.881 VidPlayback[2108:b203] INFO/AR(2108) 2015-05-27 22:48:37: ObjectTracker: Successfully created dataset

2015-05-27 22:48:37.887 VidPlayback[2108:b203] INFO: successfully loaded data set

2015-05-27 22:48:38.341 VidPlayback[2108:b203] INFO: successfully activated data set

2015-05-27 22:48:38.421 VidPlayback[2108:b203] *** -[AVCaptureVideoDataOutput setVideoSettings:] - videoSettings dictionary contains one or more unsupported (ignored) keys: (





2015-05-27 22:48:38.444 VidPlayback[2108:b203] DEBUG/AR(2108) UIView has CAEAGLLayer class

2015-05-27 22:48:38.449 VidPlayback[2108:b203] DEBUG/AR(2108) UIView responds to selector renderFrameQCAR</pre>

black screen on 2nd time loading app

June 11, 2015 - 2:11pm #8

So the minimum iPhone supporting Vuforia 4.x is the iPhone 4S. I was able to reproduce the black video background on an iPhone 4 as well. The tracking and augmentation displayed okay. The iPhone 4 also can't upgrade to iOS 8 which is now required to submit to App Store.

black screen on 2nd time loading app

June 11, 2015 - 1:08pm #7

yeah the iphone 4 is old, and it seems to be the only device I'm having this problem with, as now I've tried it on an ipad and an iphone 6 with no problems. I'd stil love to know why this is happening, as I would love my app to work with as many ios devices as possible.

If I force quit the app (double home tap, and swipe), I still get the same issue.

same issue with the 4.0.103 sdk. works on the initial build but then not after that.


again, for the other people in this thread, I am not having a unity issue as I'm not using unity. Just straight up sdk sample. There are lots of threads with the same issue for unity though. 

black screen on 2nd time loading app

June 11, 2015 - 4:45am #6

I'm having the same issue.
Unity 4.6.5
Vuforia 4.2.3

First time loaded up is fine. Here is the crash log:

2015-06-11 11:46:43.626 sg360[343:60b] ERROR/AR(343) 2015-06-11 11:46:43: VideoBackgroundConfig with screen size of zero received, skipping config step
OpenGLES error 0x0500 in /Classes/Unity/GlesHelper.mm:338
Tracked Show_ARInstructions
UnityEngine.Debug:Internal_Log(Int32, String, Object)
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7-il2cppGenerated/UnityEngineDebug.cpp Line: 56)
OpenGLES error 0x0500 in /Classes/Unity/GlesHelper.mm:338
OpenGLES error 0x0500 in /Classes/Unity/GlesHelper.mm:338
OpenGLES error 0x0500 in /Classes/Unity/GlesHelper.mm:338
OpenGLES error 0x0500 in /Classes/Unity/GlesHelper.mm:338
OpenGLES error 0x0500 in /Classes/Unity/GlesHelper.mm:338

black screen on 2nd time loading app

June 4, 2015 - 10:16am #5

Samething happened for me. Please just upgrade your unity into unity 4.6.5 or so and use vuforia 4.2.3 then everything will works fine.

black screen on 2nd time loading app

June 1, 2015 - 8:22pm #4

  • The iPhone 4 is pretty old. Have you tried this on any other iOS device?
  • If you quit the app from memory (not delete) will it work on a restart?
  • Did this work on any SDK versions prior to 4.2.3? If so, which ones?

black screen on 2nd time loading app

May 28, 2015 - 9:08pm #3

Hi dm3d,


 Thanks for you help with this. I'm using an iphone 4  ios version 7.1.2. Yes it continues to happen when unplugged (it continues to not display that is). Same deal with the dominoes sample, works after the first build, but then after that all I get is a black screen. I have to delete the sample off the phone, build and then it will work the first time again.

black screen on 2nd time loading app

May 28, 2015 - 6:06pm #2

  • What device and OS version is this seen on?
  • Does it continue to happen if you unplug device from computer?
  • Are other samples affected or just VideoPlayback?
Log in or register to post comments