我仔细遵循（重复两次）所有先决条件，并成功连接到Azure IoT中心。已上载设备代码入门示例（将IoT DevKit传感器数据发送到IoT中心）。并且在最后一步中出现以下错误。
[Starting] Opening the serial port - COM4
[Info] Opened the serial port - COM4
2019-02-09 06:31:12 INFO: >>>IoTHubClient_LL_SendEventAsync accepted message for transmission to IoT Hub.
2019-02-09 06:31:17 ERROR: File:C:\Users\v-zuhu\AppData\Local\Arduino15\packages\AZ3166\hardware\stm32f4\1.6.0\cores\arduino\azure-iot-sdk-c\iothub_client\src\iothubtransport_mqtt_common.c Func:mqtt_operation_complete_callback Line:1724, Connection Not Accepted: 0x5: Not Authorized
[Done] Closed the serial port
我尝试从头开始重新创建示例，并在DevKitDPS.ino上传过程中注意到以下类型的多个错误：
..\AppData\Local\Arduino15\packages\AZ3166\hardware\stm32f4\1.6.1\system/platform/toolchain.h:23:2: warning: #warning toolchain.h has been replaced by mbed_toolchain.h, please update to mbed_toolchain.h [since mbed-os-5.3] [-Wcpp]
#warning toolchain.h has been replaced by mbed_toolchain.h, please update to mbed_toolchain.h [since mbed-os-5.3]
..\examples\devkit_dps\Device\DevKitDPS.ino:12:32: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
char* Global_Device_Endpoint = "global.azure-devices-provisioning.net";
研究了此问题，发现以下链接：
https://github.com/ARMmbed/mbed-os/issues/3876
toolchain.h has been replaced by mbed_toolchain.h
我没有进行此操作的任何指导，将不胜感激。