APP崩溃提示：This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes.

崩溃输出日志

2017-08-29 14:53:47.332368+0800 HuiDaiKe[2373:1135604] This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes.
 Stack:(
    0   CoreFoundation                      0x0000000188e42ff8  + 148
    1   libobjc.A.dylib                     0x00000001878a4538 objc_exception_throw + 56
    2   CoreFoundation                      0x0000000188e42f28  + 0
    3   Foundation                          0x0000000189a35378  + 128
    4   Foundation                          0x000000018987da38  + 36
    5   UIKit                               0x000000018ef703b0  + 816
    6   UIKit                               0x000000018ef7c2ac  + 1740
    7   UIKit                               0x000000018f2a57f0  + 88
    8   UIKit                               0x000000018efd9b04  + 376
    9   UIKit                               0x000000018f049840  + 232
    10  UIKit                               0x000000018f0495b8  + 244
    11  UIKit                               0x000000018f0543cc  + 932
    12  UIKit                               0x000000018f053eec  + 184
    13  UIKit                               0x000000018f053914  + 1728
    14  MJRefresh                           0x00000001013c72bc -[UITableView(MJRefresh) mj_reloadData] + 40
    15  HuiDaiKe                            0x000000010013e440 _TFC8HuiDaiKe40CustomersAddressBookImportViewControllerP33_17FF30CE5B34E964041849EE3753856C13setDataSourcefGSaCS_19cwsAddressBookModel_T_ + 2728
    16  HuiDaiKe                            0x000000010013d968 _TFFC8HuiDaiKe40CustomersAddressBookImportViewControllerP33_17FF30CE5B34E964041849EE3753856C11prepareDataFT_T_U_FTOCS_14cwsAddressBook4typeGSaCS_19cwsAddressBookModel__T_ + 992
    17  HuiDaiKe                            0x00000001001c9cc0 _TFFC8HuiDaiKe14cwsAddressBook3getFT4backFTOS0_4typeGSaCS_19cwsAddressBookModel__T__T_U_FTS1_GSaS2___T_ + 252
    18  HuiDaiKe                            0x00000001001ca5c8 _TFFFC8HuiDaiKe14cwsAddressBookP33_FC9266F7BF731B8D62B76C7FA41D90D413check_iOS_9_0FT4backFTOS0_4typeGSaCS_19cwsAddressBookModel__T__T_U0_FTSbGSqPs5Error___T_U_FTSbGSaS2___T_ + 96
    19  HuiDaiKe                            0x00000001001caa04 _TFC8HuiDaiKe14cwsAddressBookP33_FC9266F7BF731B8D62B76C7FA41D90D411get_iOS_9_0fT4backFTSbGSaCS_19cwsAddressBookModel__T__T_ + 828
    20  HuiDaiKe                            0x00000001001ca544 _TFFC8HuiDaiKe14cwsAddressBookP33_FC9266F7BF731B8D62B76C7FA41D90D413check_iOS_9_0FT4backFTOS0_4typeGSaCS_19cwsAddressBookModel__T__T_U0_FTSbGSqPs5Error___T_ + 220
    21  HuiDaiKe                            0x00000001001ca6bc _TTRXFo_dSboGSqPs5Error____XFdCb_dSbdGSqCSo7NSError___ + 132
    22  ContactsFoundation                  0x0000000191862748  + 288
    23  ContactsFoundation                  0x000000019186d680  + 600
    24  Contacts                            0x00000001918c814c  + 72
    25  libdispatch.dylib                   0x0000000187cfa9e0  + 24
    26  libdispatch.dylib                   0x0000000187cfa9a0  + 16
    27  libdispatch.dylib                   0x0000000187d090d4  + 644
    28  libdispatch.dylib                   0x0000000187d0aa50  + 540
    29  libdispatch.dylib                   0x0000000187d0a7d0  + 124
    30  libsystem_pthread.dylib             0x0000000187f03100 _pthread_wqthread + 1096
    31  libsystem_pthread.dylib             0x0000000187f02cac start_wqthread + 4
)

崩溃原因

在子线程中更新UI导致主线程的视图布局出错

解决方法

把更新UI的操作放在主线程中执行

swift示例

DispatchQueue.main.async {
   self.mainTableview.reloadData()
}