title: iOS App keeps crashing for reviewer, but works fine in field tests
body: <p>my iOS app keeps crashing for the iOS reviewer team, but works fine on all kind of test flight devices (~10). I am unable to reproduce the problem.</p>
  
  <p>The crash log the reviewer team sent me states</p>
  
  <pre><code>Incident Identifier: 6686BE5C-DCC1-48C1-9AC2-FCFF85F3EBC2
  ...
  Version:             4 (2.1)
  Code Type:           ARM-64 (Native)
  ...
  Exception Type:  EXC_BREAKPOINT (SIGTRAP)
  Exception Codes: 0x0000000000000001, 0x000000010012e218
  Triggered by Thread:  5
  ...
  
  Thread 5 name:  Dispatch queue: com.apple.root.default-qos
  Thread 5 Crashed:
  0   Alamofire                       0x000000010012e218 Alamofire.request (Alamofire.Method, Alamofire.URLStringConvertible, parameters : [Swift.String : Swift.AnyObject]?, encoding : Alamofire.ParameterEncoding) -&gt; Alamofire.Request (Alamofire.swift:1522)
  1   Alamofire                       0x000000010012e058 Alamofire.request (Alamofire.Method, Alamofire.URLStringConvertible, parameters : [Swift.String : Swift.AnyObject]?, encoding : Alamofire.ParameterEncoding) -&gt; Alamofire.Request (Alamofire.swift:1522)
  2   Stundenplan                     0x000000010009d4c4 function signature specialization &lt;Arg[0] = Owned To Guaranteed&gt; of Stundenplan.TimeTableManager.loadRemote (Stundenplan.TimeTableManager)() -&gt; () (TimeTableManager.swift:103)
  3   Stundenplan                     0x000000010009e434 Stundenplan.TimeTableManager.(reload (Stundenplan.TimeTableManager) -&gt; () -&gt; ()).(closure #1) (TimeTableManager.swift:58)
  4   libdispatch.dylib               0x0000000197b29990 _dispatch_call_block_and_release + 20
  5   libdispatch.dylib               0x0000000197b29950 _dispatch_client_callout + 12
  6   libdispatch.dylib               0x0000000197b3677c _dispatch_root_queue_drain + 1844
  7   libdispatch.dylib               0x0000000197b37c48 _dispatch_worker_thread3 + 104
  8   libsystem_pthread.dylib         0x0000000197d09228 _pthread_wqthread + 812
  9   libsystem_pthread.dylib         0x0000000197d08eec start_wqthread + 0
  </code></pre>
  
  <p>which seems to point to Alamofire, but I have not found a single report about anything even close to this.</p>
  
  <p>I double checked my code for anything that could go wrong, but I still have no idea, why it keeps crashing.</p>
  
  <pre class="lang-swift prettyprint-override"><code>func loadRemote() {
      if let timeTableName = NSUserDefaults.standardUserDefaults().stringForKey("timeTable") {
          // Prevent server flooding
          if let lastUpdate = lastUpdate where lastCourse == timeTableName {
              if NSDate.minutesBetween(date1: lastUpdate, date2: NSDate()) &lt; 5 {
                  return ;
              }
          }
  
          lastUpdate = NSDate()
          lastCourse = timeTableName
  
          let icalLink = "http://****/ical/\(timeTableName).ics"
          UIApplication.sharedApplication().networkActivityIndicatorVisible = true
          Alamofire.request(.GET, icalLink).responseString { (_, _, data, err) in
              UIApplication.sharedApplication().networkActivityIndicatorVisible = false
              if(err != nil) {
                  PiwikTracker.sharedInstance().sendExceptionWithDescription("Server unreachable.", isFatal: true)
              } else {
                  if let cache = NSUserDefaults.standardUserDefaults().stringForKey("icsCache") {
                      if data == cache {
                          return
                      }
                  }
                  TimeTable(icalString: data!, success: { (timeTable) in
                      self.currentData = timeTable
                      NSUserDefaults.standardUserDefaults().setValue(data, forKey: "icsCache")
                      }, error: {
                          println("error parsing timetable")
                  })
              }
          }
      }
  }
  </code></pre>
  
  <p>Any help is much appreciated.</p>
  
  <p>Thank you in advance!</p>