The app crashes by SIGABRT. What is the Root Cause?

__pthread_kill

• libsystem_pthread0x18fb7b090

  pthread_kill$VARIANT$mp

• libsystem_c0x213697ea4

  abort

• QuartzCore0x1b3b33888

  CA::Render::Encoder::grow(unsigned long)

• QuartzCore0x1b3b34954

  CA::Render::Encoder::encode_object

• QuartzCore0x1b3a1c9e8

  CA::Render::Layer::encode

• QuartzCore0x1b3b384dc

  CA::Render::encode_set_object

• QuartzCore0x1b3b31fb4

  CA::Layer::commit_if_needed

• QuartzCore0x1b3a88f40

  CA::Context::commit_root

• QuartzCore0x1b3a89b78

  CA::Context::commit_transaction

• QuartzCore0x1d6c53104

  CA::Transaction::commit

• Company0x104919268

  +[MessageBoxManager setProgress1:progress:]company

  /util/MessageBoxManager.m:311

• Company0x104936b08

  -[FormEngineScrollViewDelegate makeSureVisibleWidgetsAreLoaded:messageBoxInfoId:screenWasAutoPushed:pausedActivityWidgetFormElement:]

  Company/util/FormEngine.m:576

• Company0x1049366bc

  formEngineSetup

  Company/util/FormEngine.m:508

• Company0x10486fa44

  -[ActivityScreenViewController delaySetupForm]Company

  2/app/ActivityScreenViewController.m:982

• libdispatch0x20b72d7d0

  _dispatch_client_callout

• libdispatch0x20b6d2014

  _dispatch_continuation_pop$VARIANT$mp

• libdispatch0x200dddfa0

  _dispatch_source_invoke$VARIANT$mp

• libdispatch0x1bc766ee4

  _dispatch_main_queue_callback_4CF$VARIANT$mp

• CoreFoundation0x1fec60ebc

  __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__

• CoreFoundation0x1fec5bdf4

  __CFRunLoopRun

• CoreFoundation0x1af61f350

  CFRunLoopRunSpecific

• GraphicsServices0x215d2c798

  GSEventRunModal

• UIKitCore0x240117b64

  UIApplicationMain

• Company0x104063b20

  main

  Company/main.m:17

• libdyld0x2135f28dc

  start
  

+ (void)setProgress1:(id)messageBoxInfoId progress:(float)progress

{

MessageBoxInfo *messageBoxInfo = (MessageBoxInfo *)messageBoxInfoId;

if ([NSThread isMainThread])

{

[instance setProgress1:messageBoxInfo progress:progress];

[CATransaction flush]; // This is the line 311

}

else

{

dispatch_async(dispatch_get_main_queue(),

^{

@autoreleasepool

{

@synchronized (instance)

{

[instance setProgress1:messageBoxInfo progress:progress];

}

}

});

}

}