ts-4.2.0 traffic_server crashes frequently

/opt/ats/bin/traffic_server - STACK TRACE:
/lib64/libpthread.so.0[0x38afc0f500]
/opt/ats/bin/traffic_server(mime_field_value_get(MIMEField*, int*)+0x0)[0x5beb50]
/opt/ats/bin/traffic_server(HttpTransact::build_response(HttpTransact::State*, HTTPHdr*, HTTPHdr*, HTTPVersion, HTTPStatus, char const*)+0x455)[0x5447b5]
/opt/ats/bin/traffic_server(HttpTransact::handle_cache_operation_on_forward_server_response(HttpTransact::State*)+0x777)[0x54efd7]
/opt/ats/bin/traffic_server(HttpTransact::HandleResponse(HttpTransact::State*)+0x17a)[0x5591aa]
/opt/ats/bin/traffic_server(HttpSM::call_transact_and_set_next_state(void (*)(HttpTransact::State*))+0x66)[0x515996]
/opt/ats/bin/traffic_server(HttpSM::handle_api_return()+0x37a)[0x52e95a]
/opt/ats/bin/traffic_server(HttpSM::state_read_server_response_header(int, void*)+0x36a)[0x523afa]
/opt/ats/bin/traffic_server(HttpSM::main_handler(int, void*)+0xd8)[0x525da8]
/opt/ats/bin/traffic_server[0x685fbb]
/opt/ats/bin/traffic_server[0x6886d4]
/opt/ats/bin/traffic_server(NetHandler::mainNetEvent(int, Event*)+0x1f2)[0x67e312]
/opt/ats/bin/traffic_server(EThread::process_event(Event*, int)+0x8f)[0x6aaacf]
/opt/ats/bin/traffic_server(EThread::execute()+0x44b)[0x6ab30b]
/opt/ats/bin/traffic_server[0x6a9e5a]
/lib64/libpthread.so.0[0x38afc07851]
/lib64/libc.so.6(clone+0x6d)[0x38af8e767d]