The same client connected to version 3.1 is normal, but abnormal when connecting to version 4.0 #3315
Description
Environment
- OS: win10
- Erlang/OTP:
- EMQ: 4.0
Description
使用hivemq-client 1.1.4版本连接emq3.1版本正常，连接4.0版本提示错误（ConnAck 中Maximum QoS 返回值为2），联系客户端作者，得到如下反馈：
Followed by a Byte with a value of either 0 or 1. It is a Protocol Error to include Maximum QoS more than once, or to have a value other than 0 or 1. If the Maximum QoS is absent, the Client uses a Maximum QoS of 2.
可查看 https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901084