Exception caught by gesture

[subhangpati]

The following NoSuchMethodError was thrown while handling a gesture:
The getter 'email' was called on null.
Receiver: null
Tried calling: email
// This is the message that I am getting

Need help to resolve this.

flutter/flutter#62747
Here is the full code I posted on official flutter community

[Nik8110]

FlatButton(
onPressed: () {
//Implement send functionality.
_firestore.collection('message').add({
'sender':_auth.currentUser.email,
'send': messages,
});
},

simply put this