title: CoreData MagicalRecord save methods crashes on iPhone5
body: <p>Currently I'm working with <code>MagicalRecord v2.3.0-beta.3 commit:d18e74fe435359238b9593c03e41c1ee0baa0b78</code> framework. I'm getting 1 a crash log (from <code>Crashlytics</code>) on iPhone 5 all the time. App is still in development. The crash log looks like below:</p>
  
  <pre><code>Thread : Crashed: com.apple.main-thread
  0  libobjc.A.dylib                0x38eee626 objc_msgSend + 5
  1  Foundation                     0x2f06d02d -[NSError dealloc] + 60
  2  libobjc.A.dylib                0x38ef3b6b objc_object::sidetable_release(bool) + 174
  3  libobjc.A.dylib                0x38ef40d3 (anonymous namespace)::AutoreleasePoolPage::pop(void*) + 358
  4  CoreFoundation                 0x2e67d481 _CFAutoreleasePoolPop + 16
  5  Foundation                     0x2f0778e3 -[NSAutoreleasePool drain] + 122
  6  CoreData                       0x2e4bdfbf -[NSManagedObjectContext save:] + 942
  7  MyApp                          0x00162f9f __70-[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:]_block_invoke15 (NSManagedObjectContext+MagicalSaves.m:82) // here app crashes
  8  CoreData                       0x2e5219cd developerSubmittedBlockToNSManagedObjectContextPerform + 88
  9  CoreData                       0x2e521b13 -[NSManagedObjectContext performBlockAndWait:] + 114
  10 MyApp                          0x00162e51 -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:] (NSManagedObjectContext+MagicalSaves.m:116)
  11 MyApp                          0x000a2b0d -[SPNCoreDataHandler parseAndSaveDictionaryReturnOperationArray:withSaving:] (SPNCoreDataHandler.m:70)
  12 MyApp                          0x00078f21 __102-[SPNApiHandler getAllDataWithDownloadingSuccessBlock:savingSuccessBlock:downloadStatus:failureBlock:]_block_invoke (SPNApiHandler.m:69)
  13 MyApp                          0x000795b9 __66-[SPNApiHandler sendGetRequestWithPath:successBlock:failureBlock:]_block_invoke (SPNApiHandler.m:174)
  14 libdispatch.dylib              0x393cdd53 _dispatch_call_block_and_release + 10
  15 libdispatch.dylib              0x393cdd3f _dispatch_client_callout + 22
  16 libdispatch.dylib              0x393d06c3 _dispatch_main_queue_callback_4CF + 278
  17 CoreFoundation                 0x2e714641 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
  18 CoreFoundation                 0x2e712f0d __CFRunLoopRun + 1308
  19 CoreFoundation                 0x2e67d729 CFRunLoopRunSpecific + 524
  20 CoreFoundation                 0x2e67d50b CFRunLoopRunInMode + 106
  21 GraphicsServices               0x335ec6d3 GSEventRunModal + 138
  22 UIKit                          0x30fde871 UIApplicationMain + 1136
  23 MyApp                          0x0009c347 main (main.m:16)
  </code></pre>
  
  <p>And here's code which I wrote:</p>
  
  <p><strong>NOTE:</strong> I removed some parts of this method for sake of readability (that's why method returns void instead of NSArray).</p>
  
  <pre><code>- (NSArray *)parseAndSaveDictionaryReturnOperationArray:(NSDictionary *)dictionary withSaving:(BOOL)saveSynchrounously {
  
      [self truncateAll]; //method which removes all entries in coreData
  
      /* methods below creates entities from array given in dictionary
         using [NSManagedObject MR_createEntity] method 
         e.g. Contact *contact = [Contact MR_createEntity]; */
  
      [self saveContacts:dictionary[@"contact"]];
      [self savePeople:dictionary[@"person"]];
      [self saveBuildings:dictionary[@"place"]];
      [self saveSessions:dictionary[@"session"]];
      [self saveLectures:dictionary[@"program"]];
      [self savePartners:dictionary[@"partners"]];
      [self saveSponsors:dictionary[@"sponsors"]];
      [self saveExhibitorsPlans:dictionary[@"exhibitorplan"]];
      [self saveMeetingPlans:dictionary[@"meetingplan"]];
      [self saveOrganizationalInformation:dictionary[@"info"]];
  
      [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];
  
      //continue executing method...
  }
  </code></pre>
  
  <p>I tried also to use <code>[[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreWithCompletion:]</code> method but it crashes too.</p>
  
  <p>In other Stackoverflow question someone suggested, that crash can be caused by deleting, creating and saving to many entities at once. In my case it's around 200 deleted entities + 200 new ones. Can it cause crash?</p>
  
  <p>On other devices (iPhone 4s, iPhone 5s, iPad 2, iPad4, iPad mini) it works fine. Any ideas what I'm doing wrong?</p>