title: Crash in background- Sprite-Kit related
body: <p>As the title says- my Sprite Kit game crashes every now and then in background, always with this error-</p>
  
  <pre><code>Exception Type:  EXC_BAD_ACCESS (SIGSEGV) 
  Exception Subtype: KERN_INVALID_ADDRESS at 0x00000001
  Triggered by Thread:  0
  Thread 0 Crashed:
  
  0   libGPUSupportMercury.dylib      0x3220193a gpus_ReturnNotPermittedKillClient + 10
  1   libGPUSupportMercury.dylib      0x322023d4 gpusSubmitDataBuffers + 100
  2   IMGSGX543RC2GLDriver            0x2c6211c4 SubmitPackets + 120
  3   GLEngine                        0x2fb3bcda gliPresentViewES + 162
  4   OpenGLES                        0x2fb46134 -[EAGLContext presentRenderbuffer:] + 60
  5   SpriteKit                       0x2ffb0060 -[SKView _renderContent] + 1216
  6   libdispatch.dylib               0x381120ec _dispatch_client_callout + 20
  7   libdispatch.dylib               0x381168f6 _dispatch_barrier_sync_f_invoke + 22
  8   SpriteKit                       0x2ffafb6e -[SKView renderContent] + 78
  9   SpriteKit                       0x2ffad516 __29-[SKView setUpRenderCallback]_block_invoke + 126
  10  SpriteKit                       0x2ffcfc84 -[SKDisplayLink _callbackForNextFrame:] +     252
  11  QuartzCore                      0x2fd9003e CA::Display::DisplayLinkItem::dispatch() +     94
  12  QuartzCore                      0x2fd8fde8 CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) + 340
  13  IOMobileFramebuffer             0x329b876a IOMobileFramebufferVsyncNotifyFunc + 102
  14  IOKit                           0x2e614e6a IODispatchCalloutFromCFMessage + 246
  15  CoreFoundation                  0x2d8f2b86 __CFMachPortPerform + 134
  16  CoreFoundation                  0x2d8fd77c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 32
  17  CoreFoundation                  0x2d8fd716 __CFRunLoopDoSource1 + 342
  18  CoreFoundation                  0x2d8fbee2 __CFRunLoopRun + 1402
  19  CoreFoundation                  0x2d86653c CFRunLoopRunSpecific + 520
  20  CoreFoundation                  0x2d86631e CFRunLoopRunInMode + 102
  21  GraphicsServices                0x3259d2e6 GSEventRunModal + 134
  22  UIKit                           0x3011d1e0 UIApplicationMain + 1132
  23  NoCar7                          0x0010c186 0xf9000 + 78214
  24  libdyld.dylib                   0x38126ab4 start + 0
  
  Thread 1:
  0   libsystem_kernel.dylib          0x381ca838 kevent64 + 24
  1   libdispatch.dylib               0x381190d0 _dispatch_mgr_invoke + 228
  2   libdispatch.dylib               0x3811363e _dispatch_mgr_thread + 34
  
  Thread 2:
  0   libsystem_kernel.dylib          0x381ddc7c __workq_kernreturn + 8
  1   libsystem_pthread.dylib         0x38241e06 _pthread_wqthread + 306
  2   libsystem_pthread.dylib         0x38241cc0 start_wqthread + 4
  
  Thread 3:
  0   libsystem_kernel.dylib          0x381ddc7c __workq_kernreturn + 8
  1   libsystem_pthread.dylib         0x38241e06 _pthread_wqthread + 306
  2   libsystem_pthread.dylib         0x38241cc0 start_wqthread + 4
  
  Thread 4:
  0   libsystem_kernel.dylib          0x381ddc7c __workq_kernreturn + 8
  1   libsystem_pthread.dylib         0x38241e06 _pthread_wqthread + 306
  2   libsystem_pthread.dylib         0x38241cc0 start_wqthread + 4
  
  Thread 5:
  0   libsystem_kernel.dylib          0x381caa84 mach_msg_trap + 20
  1   libsystem_kernel.dylib          0x381ca87c mach_msg + 36
  2   AudioToolbox                    0x2d26d99c AURemoteIO::IOThread::Run() + 184
  3   AudioToolbox                    0x2d271438 AURemoteIO::IOThread::Entry(void*) + 4
  4   AudioToolbox                    0x2d19f2ac CAPThread::Entry(CAPThread*) + 208
  5   libsystem_pthread.dylib         0x38243c5a _pthread_body + 138
  6   libsystem_pthread.dylib         0x38243bca _pthread_start + 98
  7   libsystem_pthread.dylib         0x38241ccc thread_start + 4
  
  Thread 0 crashed with ARM Thread State (32-bit):
  r0: 0xdeadbeef    r1: 0x00000001      r2: 0x1b48d000      r3: 0x00000044
  r4: 0x00000000    r5: 0x04e5d560      r6: 0x04e5d438      r7: 0x27d088c0
  r8: 0x00000000    r9: 0x00000fff     r10: 0x04e5d000     r11: 0x04e5b90f
  ip: 0x3a004114    sp: 0x27d088a0      lr: 0x322023d9      pc: 0x3220193a
  cpsr: 0x20000030
  </code></pre>
  
  <p>What can cause it?</p>