title: Network error when authenticating user with AWS Cognito
body: <p>I'm trying to incorporate Cognito authentication into my React based project. My code is based on examples given in NPM page. This is what it looks like :</p>
  
  <pre><code>var authenticationData = {
      Username : 'username',
      Password : 'password',
  };
  
  var authenticationDetails = new AmazonCognitoIdentity.AuthenticationDetails(authenticationData);
  
  var poolData = {
      UserPoolId : '...', // Your user pool id here
      ClientId : '...' // Your client id here
  };
  
  var userPool = new AmazonCognitoIdentity.CognitoUserPool(poolData);
  
  var userData = {
      Username : 'username',
      Pool : userPool
  };
  
  var cognitoUser = new AmazonCognitoIdentity.CognitoUser(userData);
  cognitoUser.authenticateUser(authenticationDetails, {
      onSuccess: function (result) {
                 console.log('Successfully logged!');
              }
          });
      },
  
      onFailure: function(err) {
          console.log(JSON.stringify(err));
      },
  
  });
  </code></pre>
  
  <p>I have created a user pool and added an app client. I have also enabled identity provider for app client. However, my code fails to authenticate with error <strong>{"code":"NetworkError","name":"Error","message":"Network error"}</strong>. Since my project is still hosted on a localhost, I have installed CORS plug-in for firefox, but that doesn't resolve the issue. I couldn't make much sense out of this error message. I have double checked Cognito region, pool id and client id. They all set to correct values. Does anyone familiar with this error and have an idea what maybe causing this?</p>