The issue started last week and is now acting also on old commits that were previously working. 

The attached picture shows what I get.

It does work fine in editor, only when we build for iOS (iPhone and iPad, did not try on Android).

I went through various black screen threads but they seem to be more about full black screen and I have the settings as recommended (32-bit display buffer and Depth only on camera).

And here is the debug from xCode from whihc I tried to strip most of the irrelevant bits.

2015-03-12 14:46:35.401 HomeSpot[1906:1018060] -> registered mono modules 0x21a2c30
-> applicationDidFinishLaunching()
Mono path[0] = '/private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed'
Mono config path = '/private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed'
-> applicationDidBecomeActive()
QCAR Extension version 3.0.0
2015-03-12 14:46:36.253 HomeSpot[1906:1018060] INFO/AR(1906) 2015-03-12 14:46:36: QCAR SDK version 3.0.9
Requesting Resolution: 1536x2048
Renderer: PowerVR SGX 554
Vendor:   Imagination Technologies
Version:  OpenGL ES 2.0 IMGSGX554-113.3
GL_OES_depth_texture GL_OES_depth24 GL_OES_element_index_uint GL_OES_fbo_render_mipmap GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_texture_float GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_vertex_array_object GL_EXT_blend_minmax GL_EXT_color_buffer_half_float GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_draw_instanced GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_pvrtc_sRGB GL_EXT_read_format_bgra GL_EXT_separate_shader_objects GL_EXT_shader_framebuffer_fetch GL_EXT_shader_texture_lod GL_EXT_shadow_samplers GL_EXT_sRGB GL_EXT_texture_filter_anisotropic GL_EXT_texture_rg GL_EXT_texture_storage GL_APPLE_clip_distance GL_APPLE_color_buffer_packed_float GL_APPLE_copy_texture_levels GL_APPLE_framebuffer_multisample GL_APPLE_rgb_422 GL_APPLE_sync GL_APPLE_texture_format_BGRA8888 GL_APPLE_texture_max_level GL_APPLE_texture_packed_float GL_IMG_read_format GL_IMG_texture_comp
ression_pvrtc 
Creating OpenGLES2.0 graphics device
Initialize engine version: 4.6.3f1 (4753d8b6ef2b)
Begin MonoManager ReloadAssembly
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/UnityEngine.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/UnityEngine.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/System.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Mono.Security.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/System.Configuration.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/System.Xml.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/System.Security.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Assembly-CSharp-firstpass.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Assembly-CSharp-firstpass.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/P31RestKit.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/System.Core.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Mono.Posix.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Assembly-CSharp.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Assembly-CSharp.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Qualcomm.Vuforia.UnityExtensions.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Ionic.Zip.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/UnityEngine.UI.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/UnityEngine.UI.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/UnityEngine.UI.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/P31RestKit.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/P31RestKit.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Qualcomm.Vuforia.UnityExtensions.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Qualcomm.Vuforia.UnityExtensions.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.CJK.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.CJK.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.dll (this message is harmless)
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.MidEast.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.MidEast.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.Other.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.Other.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.West.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/I18N.West.dll into Unity Child Domain
Platform assembly: /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Ionic.Zip.dll (this message is harmless)
Loading /private/var/mobile/Containers/Bundle/Application/9E375423-0468-4135-AD7C-D23292E959A2/HomeSpot.app/Data/Managed/Ionic.Zip.dll into Unity Child Domain
- Completed reload, in  0.158 seconds


Unloading 7 unused Assets to reduce memory usage. Loaded Objects now: 1303.
Total: 6.262375 ms (FindLiveObjects: 0.401416 ms CreateObjectMapping: 0.121916 ms MarkObjects: 4.778291 ms  DeleteObjects: 0.574166 ms)

QCARWrapper.Start
 
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7Generated/UnityEngineDebug.cpp Line: 56)

trackerManagerInitTracker
trackerManagerInitTracker
SetHint
 
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7Generated/UnityEngineDebug.cpp Line: 56)

Setting Unity version 4.6.3
StartQCAR
 
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7Generated/UnityEngineDebug.cpp Line: 56)

cameraDeviceInitCamera
2015-03-12 14:46:51.643 HomeSpot[1906:1018060] *** -[AVCaptureVideoDataOutput setVideoSettings:] - videoSettings dictionary contains one or more unsupported (ignored) keys: (
    Height,
    Width
)
2015-03-12 14:46:51.651 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:51.652 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:51.652 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:51.653 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:51.653 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
2015-03-12 14:46:51.654 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
cameraDeviceGetVideoMode
2015-03-12 14:46:51.666 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:51.667 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:51.668 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:51.669 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:51.670 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
2015-03-12 14:46:51.670 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
cameraDeviceSelectVideoMode
2015-03-12 14:46:51.673 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:51.673 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:51.674 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:51.674 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:51.674 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
2015-03-12 14:46:51.675 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
cameraDeviceStartCamera
markerTrackerStart
imageTrackerStart
dataSetExists
imageTrackerCreateDataSet
2015-03-12 14:46:52.201 HomeSpot[1906:1018060] INFO/AR(1906) 2015-03-12 14:46:52: ImageTracker: Successfully created dataset
Successfully created data set.
imageTrackerActivateDataSet
imageTargetBuilderStartScan
targetFinderStartInit
 

cameraDeviceGetVideoMode
2015-03-12 14:46:52.223 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:52.223 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:52.224 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView has CAEAGLLayer class
2015-03-12 14:46:52.224 HomeSpot[1906:1018060] DEBUG/AR(1906) UIView does not respond to selector renderFrameQCAR
2015-03-12 14:46:52.225 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
2015-03-12 14:46:52.225 HomeSpot[1906:1018060] DEBUG/AR(1906) Could not find a UIView with CAEAGLLayer layer class that responds to selector renderFrameQCAR
cameraDeviceGetVideoMode
targetFinderGetInitState
Setting camera clear flags to depth only
 
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7Generated/UnityEngineDebug.cpp Line: 56)

targetFinderGetInitState
targetFinderSetUIScanlineColor
targetFinderSetUIPointColor
targetFinderStartRecognition
 
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7Generated/UnityEngineDebug.cpp Line: 56)

-> applicationWillResignActive()
StopQCAR
 
(Filename: /Users/builduser/buildslave/unity/build/artifacts/iPhonePlayer-armv7Generated/UnityEngineDebug.cpp Line: 56)

markerTrackerStop
imageTrackerStop
cameraDeviceStopCamera
cameraDeviceDeinitCamera
imageTargetBuilderStopScan
-> applicationDidEnterBackground()

Any help please?