我使用Parse进行应用程序设置。最近，当我的应用程序启动时，我开始收到以下错误。
[Error]: Caught "NSInternalInconsistencyException" with reason "Tried to save an object with a new, unsaved child."
应用程序不会崩溃，因为异常被捕获。但是，我无法辨别异常的原因。下面是打印到控制台的堆栈跟踪：
(
0 CoreFoundation 0x0000000185f802f4 <redacted> + 160
1 libobjc.A.dylib 0x0000000197c4c0e4 objc_exception_throw + 60
2 CoreFoundation 0x0000000185f80218 <redacted> + 0
3 STSI 0x0000000100305e4c -[PFPointerObjectEncoder encodeParseObject:] + 116
4 STSI 0x000000010030528c -[PFEncoder encodeObject:] + 148
5 STSI 0x00000001002d0254 __129+[PFRESTQueryCommand findCommandParametersWithOrder:conditions:selectedKeys:includedKeys:limit:skip:extraOptions:tracingEnabled:]_block_invoke97 + 1752
6 CoreFoundation 0x0000000185ed47a4 <redacted> + 88
7 CoreFoundation 0x0000000185ec1cec <redacted> + 240
8 STSI 0x00000001002cfa9c +[PFRESTQueryCommand findCommandParametersWithOrder:conditions:selectedKeys:includedKeys:limit:skip:extraOptions:tracingEnabled:] + 936
9 STSI 0x00000001002cf69c +[PFRESTQueryCommand findCommandParametersForQueryState:] + 348
10 STSI 0x00000001002cf074 +[PFRESTQueryCommand findCommandForQueryState:withSessionToken:] + 84
11 STSI 0x00000001002dccdc __78-[PFQueryController findObjectsAsyncForQueryState:withCancellationToken:user:]_block_invoke + 116
12 STSI 0x000000010034f9ec __55-[BFTask continueWithExecutor:block:cancellationToken:]_block_invoke_2 + 96
13 libdispatch.dylib 0x0000000100c38fd4 _dispatch_call_block_and_release + 24
14 libdispatch.dylib 0x0000000100c38f94 _dispatch_client_callout + 16
15 libdispatch.dylib 0x0000000100c46b54 _dispatch_root_queue_drain + 2180
16 libdispatch.dylib 0x0000000100c48248 _dispatch_worker_thread3 + 132
17 libsystem_pthread.dylib 0x00000001984a922c _pthread_wqthread + 816
18 libsystem_pthread.dylib 0x00000001984a8ef0 start_wqthread + 4
).
我对这个堆栈跟踪暗示的内容毫无头绪。另外，在调试器中，我可以看到分配了许多BFT的堆栈。
引发例外的原因是什么？