Every time i try to open a photo, app crushes!

protected List<ParseObject> mMessages;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_chats,
            container, false);

    return rootView;
}

@Override
public void onResume() {
    super.onResume();

    getActivity().setProgressBarIndeterminateVisibility(true);

    ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(ParseConstants.CLASS_MESSAGES);
    query.whereEqualTo(ParseConstants.KEY_RECIPIENTS_IDS, ParseUser.getCurrentUser().getObjectId());
    query.addDescendingOrder(ParseConstants.KEY_CREATED_AT);
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> messages, ParseException e) {
            getActivity().setProgressBarIndeterminateVisibility(false);

            if (e == null) {
                //We found messages!
                mMessages = messages;

                String[] usernames = new String[mMessages.size()];
                int i = 0;
                for (ParseObject message : mMessages) {
                    usernames[i] = message.getString(ParseConstants.KEY_SENDER_NAME);
                    i++;
                }
                MessageAdapter adapter = new MessageAdapter(
                        getListView().getContext(),
                        mMessages);
                setListAdapter(adapter);
            }

        }
    });
}

@Override
public void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);

    ParseObject message = mMessages.get(position);
    String messageType = message.getString(ParseConstants.KEY_FILE_TYPE);
    ParseFile file = message.getParseFile(ParseConstants.KEY_FILE);
    Uri fileUri = Uri.parse(file.getUrl());

    if (messageType.equals(ParseConstants.TYPE_IMAGE)){
        //view the image
        Intent intent = new Intent(getActivity(), ViewImageActivity.class);
        intent.setData(fileUri);
        startActivity(intent);
    }
    else {
        //view the video
        Intent intent = new Intent(Intent.ACTION_VIEW, fileUri);
        intent.setDataAndType(fileUri, "video/*");
        startActivity(intent);
    }
}

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

    setupActionBar();

    ImageView imageView = (ImageView)findViewById(R.id.imageView);

    Uri imageUri = getIntent().getData();

    Picasso.with(this).load(imageUri.toString()).into(imageView);

}

private void setupActionBar() {
    getActionBar().setDisplayHomeAsUpEnabled(true);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    switch (item.getItemId()) {
        case android.R.id.home:

            NavUtils.navigateUpFromSameTask(this);
            return true;
    }

    return super.onOptionsItemSelected(item);
}