While loading an embedded HTML page using an iframe tag, the application terminates abruptly

Question

iOS application is implemented in WebView format. Behavior of YouTube embedded player implemented with html in WebView is invalid. Specifically, there are the following events. While loading an embedded HTML page using an iframe tag, the application terminates abruptly. This event occurred in iOS 10.2, and it does not occur in other versions. Are there past cases and countermeasures?

The following is the contents of the application crash log.

2018-07-02 10:45:22.943 mall[21103:352187] +[CURLProtocol 
clientCertificationData], Line:69, (null)
objc[21103]: Class PLBuildVersion is implemented in both /Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 10.2.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/AssetsLibraryServices.framework/AssetsLibraryServices (0x11ff06998) and /Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 10.2.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/PhotoLibraryServices.framework/PhotoLibraryServices (0x11fd28880). One of the two will be used. Which one is undefined.
2018-07-02 10:45:24.578459 mall[21103:352322] [] __nwlog_err_simulate_crash_libsystem libsystem simulate crash unavailable "libsystem_network.dylib: nw_host_stats_add_src :: received error for SRC_ADDED: [22] Invalid argument"
2018-07-02 10:45:24.579614 mall[21103:352322] [] nw_host_stats_add_src received error for SRC_ADDED: [22] Invalid argument, dumping backtrace:
        [x86_64] libnetcore-856.30.16
    0   libsystem_network.dylib             0x000000010e167666 __nw_create_backtrace_string + 123
    1   libsystem_network.dylib             0x000000010e17e2f6 nw_get_host_stats + 1083
    2   libnetwork.dylib                    0x000000010e45ee9f nw_endpoint_resolver_start_next_child + 1382
    3   libdispatch.dylib                   0x000000010dee4978 _dispatch_call_block_and_release + 12
    4   libdispatch.dylib                   0x000000010df0e0cd _dispatch_client_callout + 8
    5   libdispatch.dylib                   0x000000010deebe17 _dispatch_queue_serial_drain + 236
    6   libdispatch.dylib                   0x000000010deecb4b _dispatch_queue_invoke + 1073
    7   libdispatch.dylib                   0x000000010deef385 _dispatch_root_queue_drain + 720
    8   libdispatch.dylib                   0x000000010deef059 _dispatch_worker_thread3 + 123
    9   libsystem_pthread.dylib             0x000000010e2c2169 _pthread_wqthread + 1387
    10  libsystem_pthread.dylib             0x000000010e2c1be9 start_wqthread + 13

Also, the remote debugging log of with safari web inspector is as follows.

Blocked a frame with origin "https://www.youtube.com" from accessing a frame with origin "https://xxx". Protocols, domains, and ports must match