Crash in [MediaDownloader setURL:contentInfo:]

[LaughingLife]

Thread 1: 0 libsystem_pthread.dylib 0x000000023aebfcd0 start_wqthread + 0

Thread 2 name: Dispatch queue: NSOperationQueue 0x2822f4ac0 (QOS: UNSPECIFIED) Thread 2 Crashed: 0 libobjc.A.dylib 0x000000023a48f530 objc_msgSend + 16 1 YouJiang 0x00000001056293ac -[MediaDownloader setURL:contentInfo:] + 152 2 YouJiang 0x00000001056132c0 __45-[HTTPAsyncCacheReponse delayResponseHeaders]_block_invoke + 964 3 CFNetwork 0x000000023b870688 __75-[__NSURLSessionLocal taskForClass:request:uploadFile:bodyData:completion:]_block_invoke + 32 4 CFNetwork 0x000000023b884220 __49-[__NSCFLocalSessionTask _task_onqueue_didFinish]_block_invoke + 176 5 Foundation 0x000000023bd00f68 NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK + 16 6 Foundation 0x000000023bc0d420 -[NSBlockOperation main] + 72 7 Foundation 0x000000023bc0c908 -[__NSOperationInternal _start:] + 740 8 Foundation 0x000000023bd02cec __NSOQSchedule_f + 272 9 libdispatch.dylib 0x000000023acdca38 _dispatch_call_block_and_release + 24 10 libdispatch.dylib 0x000000023acdd7d4 _dispatch_client_callout + 16 11 libdispatch.dylib 0x000000023ac82018 _dispatch_continuation_pop$VARIANT$mp + 412 12 libdispatch.dylib 0x000000023ac816dc _dispatch_async_redirect_invoke + 600 13 libdispatch.dylib 0x000000023ac8e02c _dispatch_root_queue_drain + 372 14 libdispatch.dylib 0x000000023ac8e8d0 _dispatch_worker_thread2 + 128 15 libsystem_pthread.dylib 0x000000023aebd1b4 _pthread_wqthread + 464 16 libsystem_pthread.dylib 0x000000023aebfcd4 start_wqthread + 4

最近在使用的时候，首页列表切换播放视频的时候，有几率报这个异常