Can't Pass Null For Argument 'pathstring' In Child()? This The Error I'm Getting When Retrieving Data From Firebase

I'm creating an app with firebase as a backend, First I got output but after few changes I did for intent then it shows like this, Can anyone help me to solve this error. I used if

Solution 1:

you get null value through intent here is the issue

UsersId  = getIntent().getStringExtra("User");

if(!TextUtils.isEmpty(UsersId))

then call firebase