title: SKPaymentQueue Crashing on 'NotifyObserverAboutChanges'
body: <p>please be patient.</p>
  
  <p>I am a beginner on StoreKit and I'm having a really tough time with this.</p>
  
  <p>The configuration for In App Purchase is all done and I managed to make some previous tests already. But now the app is crashing every other time after launching. Apparently the problem is this error bellow:</p>
  
  <pre><code>* thread #1: tid = 0x38d39, 0x00000001902a4bb4 libobjc.A.dylib`lookUpImpOrForward + 80, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x1a10058f938)
      frame #0: 0x00000001902a4bb4 libobjc.A.dylib`lookUpImpOrForward + 80
      frame #1: 0x00000001902af258 libobjc.A.dylib`_objc_msgSend_uncached + 56
      frame #2: 0x000000019e2fa120 StoreKit`__NotifyObserverAboutChanges + 84
      frame #3: 0x000000019173b9a8 CoreFoundation`CFArrayApplyFunction + 68
      frame #4: 0x000000019e2fa0b0 StoreKit`-[SKPaymentQueue _notifyObserversAboutChanges:sendUpdatedDownloads:] + 148
      frame #5: 0x000000019e2fabec StoreKit`-[SKPaymentQueue _processUpdates:trimUnmatched:sendUpdatedDownloads:] + 1288
      frame #6: 0x000000019e2fb47c StoreKit`-[SKPaymentQueue _setTransactionsWithReply:] + 196
      frame #7: 0x000000019e2f9b2c StoreKit`__38-[SKPaymentQueue _establishConnection]_block_invoke_2 + 64
      frame #8: 0x0000000101ad525c libdispatch.dylib`_dispatch_call_block_and_release + 24
      frame #9: 0x0000000101ad521c libdispatch.dylib`_dispatch_client_callout + 16
      frame #10: 0x0000000101ada284 libdispatch.dylib`_dispatch_main_queue_callback_4CF + 1200
      frame #11: 0x000000019180ff2c CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
      frame #12: 0x000000019180db18 CoreFoundation`__CFRunLoopRun + 1660
      frame #13: 0x000000019173c048 CoreFoundation`CFRunLoopRunSpecific + 444
      frame #14: 0x00000001931c2198 GraphicsServices`GSEventRunModal + 180
      frame #15: 0x00000001977282fc UIKit`-[UIApplication _run] + 684
      frame #16: 0x0000000197723034 UIKit`UIApplicationMain + 208
    * frame #17: 0x000000010010b8b8 Otelo`main + 140 at AppDelegate.swift:17
      frame #18: 0x00000001907205b8 libdyld.dylib`start + 4
  </code></pre>
  
  <p>I've tried to look for zombies using Instruments and I got this message:</p>
  
  <blockquote>
    <p>An Objective-C message was sent to a deallocated 'OneSignalTrackIAP'
    object (zombie) at address: 0x170017100.</p>
  </blockquote>
  
  <p>Also this Events Detail:</p>
  
  <p><a href="https://i.stack.imgur.com/EZ5Gz.png" rel="nofollow noreferrer">Instruments Stack Trace</a></p>
  
  <p>So presumably, this error comes from this "__NotifyObserverAboutChanges".</p>
  
  <p>I have no idea what to do from here. I have removed all my pods which are somehow linked to StoreKit and also all my methods and classes for In App Purchases, but it this error continues. Apparently OneSignal, my Push Notification Provider, has this In App Purchase Tracker which is throwing this crash.</p>
  
  <p>I would really appreciate if someone could give me an insight to what I should do. I feel like knocking my head against the wall right now.</p>
  
  <p>Thanks in advance.</p>