Android : Simple List View in Andriod crashes if ArrayList is not empty

Hello i have a Problem with a ListView

Here my Code

private void setViewProtocol() {
        setContentView(R.layout.protocol);
        List<String> logs = new ArrayList<String>();
        logs.add("TEST 1");

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                R.layout.protocol, logs);
        ListView lv = (ListView) findViewById(R.id.listView1);
        lv.setAdapter(adapter);
}

It crashes - but when I remove the line logs.add("TEST 1"); it works

Can anyone help me - why does it work when I call it with an emty list

Thanks