NullPointException in Prompter Class - TreeStory2

package com.teamtreehouse;

import java.io.IOException;

public class Main {

    public static void main(String[] args) {
        try {
            Prompter prompter = new Prompter();
            Template template = new Template(prompter.getStory());
            prompter.run(template);
        } catch (IOException e) {
            System.out.println("There was a problem With the madLib");
            e.printStackTrace();
            System.exit(0);
        }



    }
}

package com.teamtreehouse;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Prompter {
    private BufferedReader mReader;
    private Set<String> mCensoredWords;

    public Prompter() {
        mReader = new BufferedReader(new InputStreamReader(System.in));
        loadCensoredWords();
    }

    private void loadCensoredWords() {
        mCensoredWords = new HashSet<String>();
        Path file = Paths.get("resources", "censored_words.txt");
        List<String> words = null;
        try {
            words = Files.readAllLines(file);
        } catch (IOException e) {
            System.out.println("Couldn't load censored words");
            e.printStackTrace();
        }
        mCensoredWords.addAll(words);
    }

    public String getStory() throws IOException {
        String intro = "We are going to do a mad lib.  Surround words" +
                "You want to replace with __ like so (__noun__)";

        System.out.printf("%s%n", intro);
        String story = mReader.readLine();
        return story;
    }

    public void run(Template tmpl) {
        List<String> results = null;
        try {
            results = promptForWords(tmpl);
        } catch (IOException e) {
            System.out.println("There was a problem prompting for words");
            e.printStackTrace();
            System.exit(0);
        }
        String finalString = tmpl.render(results);
        System.out.printf("Your TreeStory: %n%s", finalString);
    }

    /**
     * Prompts user for each of the blanks
     *
     * @param tmpl The compiled template
     * @return
     * @throws IOException
     */
    public List<String> promptForWords(Template tmpl) throws IOException {
        List<String> words = new ArrayList<String>();
        for (String phrase : tmpl.getPlaceHolders()) {
            String word = promptForWord(phrase);
            words.add(word);
        }
        return words;
    }

    /**
     * Prompts the user for the answer to the fill in the blank.  Value is guaranteed to be not in the censored words list.
     *
     * @param phrase The word that the user should be prompted.  eg: adjective, proper noun, name
     * @return What the user responded
     */


 public String promptForWord(String phrase) throws IOException {
        System.out.printf("Give me a word to replace %s%n", phrase);
        String answer = mReader.readLine().trim();

        while (!isLegal(answer)) {
            System.out.printf("%s is not a legal word.  Please try again%n", answer);
            if (mReader.readLine() != null){
                answer = mReader.readLine();
            }
        }
        return answer;
    }

    public boolean isLegal(String word)  {

         if (!mCensoredWords.contains(word) && !word.matches(".*\\d+.*")) {
             return true;
         }
         return false;
    }
}