Main Thread Checker: UI API called on a background thread

[ajithrnayak]

It seems like FastttCamera is using background thread to access UI API. Enabled Main Thread Checker using Xcode 9 Apple Doc.

Happens in FastttCamera.m line number 610

Here's the backtrace after pausing execution.

=================================================================
Main Thread Checker: UI API called on a background thread: -[UIView bounds]
PID: 2754, TID: 1011164, Thread name: (none), Queue name: com.apple.root.default-qos, QoS: 21
Backtrace:
4   FastttCamera                        0x00000001026d7d98 __107-[FastttCamera _processImage:withCropRect:maxDimension:fromCamera:needsPreviewRotation:previewOrientation:]_block_invoke + 708
5   libdispatch.dylib                   0x0000000109cc12cc _dispatch_call_block_and_release + 24
6   libdispatch.dylib                   0x0000000109cc128c _dispatch_client_callout + 16
7   libdispatch.dylib                   0x0000000109ccd3dc _dispatch_queue_override_invoke + 984
8   libdispatch.dylib                   0x0000000109cd29d0 _dispatch_root_queue_drain + 624
9   libdispatch.dylib                   0x0000000109cd26f4 _dispatch_worker_thread3 + 136
10  libsystem_pthread.dylib             0x0000000185beb06c _pthread_wqthread + 1268
11  libsystem_pthread.dylib             0x0000000185beab6c start_wqthread + 4
2017-12-05 20:12:47.092293+0530 App-Dev[2754:1011164] [reports] Main Thread Checker: UI API called on a background thread: -[UIView bounds]
PID: 2754, TID: 1011164, Thread name: (none), Queue name: com.apple.root.default-qos, QoS: 21
Backtrace:
4   FastttCamera                        0x00000001026d7d98 __107-[FastttCamera _processImage:withCropRect:maxDimension:fromCamera:needsPreviewRotation:previewOrientation:]_block_invoke + 708
5   libdispatch.dylib                   0x0000000109cc12cc _dispatch_call_block_and_release + 24
6   libdispatch.dylib                   0x0000000109cc128c _dispatch_client_callout + 16
7   libdispatch.dylib                   0x0000000109ccd3dc _dispatch_queue_override_invoke + 984
8   libdispatch.dylib                   0x0000000109cd29d0 _dispatch_root_queue_drain + 624
9   libdispatch.dylib                   0x0000000109cd26f4 _dispatch_worker_thread3 + 136
10  libsystem_pthread.dylib             0x0000000185beb06c _pthread_wqthread + 1268
11  libsystem_pthread.dylib             0x0000000185beab6c start_wqthread + 4

[harshad1242]

i am facing same issue now. when device is in debug mode. else working properly