Here's the code:

```
<RelativeLayout android:id="@+id/TextDisplayLayout"
    android:layout_width="match_parent"
    android:layout_height="@dimen/PrintSetupTextHeight"
    android:layout_marginTop="45dp"
    android:layout_marginBottom="15dp">
</RelativeLayout>

```

and

```
public class MainScreen extends ActionBarActivity {

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

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment()).commit();
    }

    RelativeLayout infoDisplay = (RelativeLayout) findViewById(R.id.TextDisplayLayout);
    TextView sdCardInfo = new TextView(this);
    sdCardInfo.setId(1);
    sdCardInfo.setText("SD Card Info Here");
    sdCardInfo.setLayoutParams(new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 100));
    sdCardInfo.setBackgroundColor(Color.GRAY);
    sdCardInfo.setGravity(Gravity.CENTER);
    infoDisplay.addView(sdCardInfo);

}

```

I've narrowed down the problem to  

 infoDisplay.addView(sdCardInfo);

The app works when this part is commented out, but obviously I need this part of the code. Does anybody know why it's not working?