Were is the Bug.......

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

  protected SharedPreferences mSharedPreferences;

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

    mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

    // Some code omitted!
  }

  public int getMeaningOfLife() {
    return mSharedPreferences.getInt("MeaningOfLife", 42);
  }

  public void setMeaningOfLife() {
    mSharedPreferences
        .edit()
        .putString("MeaningOfLife", "42")   // 42 should be an int not a String
        .commit();
  }
}