错误提示如下：
2017-06-27 17:56:59.076956 6.19html[13996:677119] [] nw_host_stats_add_src recv too small, received 24, expected 28
2017-06-27 17:56:59.113802 6.19html[13996:677119] [] ____nwlog_simulate_crash_inner_block_invoke dlopen CrashReporterSupport failed
2017-06-27 17:56:59.114346 6.19html[13996:677119] [] __nwlog_err_simulate_crash simulate crash failed "nw_socket_set_common_sockopts setsockopt SO_NOAPNFALLBK failed: [42] Protocol not available"
2017-06-27 17:56:59.179387 6.19html[13996:677119] [] nw_socket_set_common_sockopts setsockopt SO_NOAPNFALLBK failed: [42] Protocol not available, dumping backtrace:
[x86_64] libnetcore-856.30.16
0 libsystem_network.dylib 0x000000010622f666 __nw_create_backtrace_string + 123
1 libnetwork.dylib 0x0000000107115006 nw_socket_add_input_handler + 3164
2 libnetwork.dylib 0x00000001070f2555 nw_endpoint_flow_attach_protocols + 3768
3 libnetwork.dylib 0x00000001070f1572 nw_endpoint_flow_setup_socket + 563
4 libnetwork.dylib 0x00000001070f0298 -[NWConcrete_nw_endpoint_flow startWithHandler:] + 2612
5 libnetwork.dylib 0x000000010710bae1 nw_endpoint_handler_path_change + 1261
6 libnetwork.dylib 0x000000010710b510 nw_endpoint_handler_start + 570
7 libnetwork.dylib 0x00000001071231f9 nw_endpoint_resolver_start_next_child + 2240
8 libdispatch.dylib 0x0000000105fac978 _dispatch_call_block_and_release + 12
9 libdispatch.dylib 0x0000000105fd60cd _dispatch_client_callout + 8
10 libdispatch.dylib 0x0000000105fb3e17 _dispatch_queue_serial_drain + 236
11 libdispatch.dylib 0x0000000105fb4b4b _dispatch_queue_invoke + 1073
12 libdispatch.dylib 0x0000000105fb7385 _dispatch_root_queue_drain + 720
13 libdispatch.dylib 0x0000000105fb7059 _dispatch_worker_thread3 + 123
14 libsystem_pthread.dylib 0x000000010637f4de _pthread_wqthread + 1129
15 libsystem_pthread.dylib 0x000000010637d341 start_wqthread + 13
解决办法如下：
1.选择Product->Scheme->Edit Scheme
2.选择Arguments
3.在Environment Variables添加一个环境变量OS_ACTIVITY_MODE 设置值为”disable”
4.然后clean和build一下就好了
如图：
