电脑通过串口，用指令与ESP8266通讯，时常会发生异常，求大神指导

问题报错：
“Invalid character found in method name. HTTP method names must be tokens

Description The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing)”
操作过程：我用网络调试助手，在电脑上建了一个TCP SERVER（见附件1

IP地址是：192.168.0.203，端口：80，然后在xcom上向ESP8266发送指令
刚开始能正常接收到ESP8266返回的“OK”等信息（见附件2），

突然不管发送什么命令，都会报错，关掉XCOM再打开，ESP8266断电再上电后才能重新正常发送和接收指令，发送几个后又重复之前的报错。见附件3