尝试获取电子邮件ID时，系统在注册期间引发异常

尝试检查unique emailID时，系统引发异常。我需要做的就是如果数据库中存在输入的电子邮件ID，系统应该向“注册”屏幕发送一条消息Player with same email address already exists !

我收到的电子邮件计数为1，但发生以下错误。

PUT http://localhost:8000/service/player 500 (Internal Server Error)
dispatchXhrRequest  @   xhr.js:178
xhrAdapter  @   xhr.js:12
dispatchRequest @   dispatchRequest.js:52
Promise.then (async)        
request @   Axios.js:61
Axios.<computed>    @   Axios.js:86
wrap    @   bind.js:9
fetchData   @   Register.js:56
onSubmit    @   Register.js:72

server.js

app.put('/service/player', async (req, res, next) => {
  try {
    const userEmail = req.body.email;
    const playerEmail = await UserModel.count({ where: { email: userEmail } }); 
    if(playerEmail==0){
      //If there is no email found, procced with normal registration here...
    const addPlayer = await UserModel.create(req.body);
    console.log("Server side PUT method log:" + addPlayer);
    res.status(200).json({ success: true });
    }else{
      return res.status(500).json({ message: "Email address already exists !"});
    }
  } catch (err) {
    return next(err);
  }
});

Register.js

    const [helperText, setHelperText] = useState('');
    const onSubmit  = () => {
    const fetchData = async () => {
      try {
     const res = await axios.put('http://localhost:8000/service/player', formRegister);
        console.log("Front End success message:" + res.data.success);
        if (res.data.success) {
          setIsSent(true);
          history.push('/login')
        }
        else {
          setHelperText(res.data.message);
        }
      } catch (e) {
        setHelperText(e.response.data.message);
      }
    }
    fetchData();
  }


<span className="registerValidationText">{helperText}</span>