SharedPreferencesApp crashing! Please help and Happy Thanksgiving :)

package com.codelouisville.tinabryan.sharedpreferencesapp;

import android.content.Context;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {
    private static final String PREFS_FILE = "com.codelouisville.tinabryan.sharedpreferencesapp";
    private static final String KEY_EDITTEXT = "key_edittext";
    private SharedPreferences.Editor mEditor;
    private SharedPreferences mSharedPreferences;
    private EditText mEditText;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mEditText = (EditText) findViewById(R.id.editText);
        mSharedPreferences = getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE);
        mEditor = mSharedPreferences.edit();

        String editTextString  = mSharedPreferences.getString(KEY_EDITTEXT, "");
        mEditText.setText(editTextString);
    }

    @Override
    protected void onPause() {
        super.onPause();

        mEditor.putString(KEY_EDITTEXT, mEditText.getText().toString());
        mEditor.apply();

    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:id="@+id/editText"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"/>
</RelativeLayout>