This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes.

2015-09-28 17:32:03.098 天天送[2079:1664555] This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes.  This will cause an exception in a future release.
Stack:(
0   CoreFoundation                      0x0000000183320f74 <redacted> + 148
1   libobjc.A.dylib                     0x0000000197f13f80 objc_exception_throw + 56
2   CoreFoundation                      0x0000000183320ea4 <redacted> + 0
3   Foundation                          0x000000018433a5d8 <redacted> + 88
4   Foundation                          0x00000001841bca1c <redacted> + 36
5   UIKit                               0x0000000188871a34 <redacted> + 532
6   UIKit                               0x0000000188b798e0 <redacted> + 228
7   UIKit                               0x0000000188870458 <redacted> + 412
8   天天送                           0x0000000100241fc4 -[UIViewController(Toast) hideLoading] + 84
9   天天送                           0x00000001001ef4c4 __51-[FudaiPayViewController wxPayWithOrderName:price:]_block_invoke + 380
10  libdispatch.dylib                   0x00000001006a9d70 _dispatch_call_block_and_release + 24
11  libdispatch.dylib                   0x00000001006a9d30 _dispatch_client_callout + 16
12  libdispatch.dylib                   0x00000001006b8f38 _dispatch_root_queue_drain + 2344
13  libdispatch.dylib                   0x00000001006b8600 _dispatch_worker_thread3 + 132
14  libsystem_pthread.dylib             0x0000000198921478 _pthread_wqthread + 1092
15  libsystem_pthread.dylib             0x0000000198921028 start_wqthread + 4
)

dispatch_async(dispatch_get_main_queue(), ^{
[weakSelf hideLoading];
});