Application is closed when new activitity is open

        public void onClick(View view) {
            CheckEditTextIsEmptyOrNot();
            if(CheckEditText){
                // If EditText is not empty and CheckEditText = True then this block will execute.
//                UserRegisterFunction(F_Name_Holder,L_Name_Holder, EmailHolder, PasswordHolder,CNIC_Holder,Phone_Holder,UsernameHolder,active);
                Intent in = new Intent(Register.this,PhoneAuthActivity.class);
                startActivity(in);
            }
            else {
                // If EditText is empty then this block will execute .
                Toast.makeText(Register.this, "Please fill all form fields.", Toast.LENGTH_LONG).show();
            }