App crashes AFTER viewing videos but not photos. Not able to return to inbox Fragment

Getting a null pointer exception on Message Adapter class after being able to watch a video.

The error is pointing to my Message adapter class, where it's loading the media icon depending on the KEY_FILE_TYPE.

    if (message.getString(ParseConstants.KEY_FILE_TYPE).equals(ParseConstants.TYPE_IMAGE)) {
        holder.iconImageView.setImageResource(R.drawable.ic_action_picture);
    } else {
        holder.iconImageView.setImageResource(R.drawable.ic_action_play_over_video);
    }
    holder.nameLabel.setText(message.getString(ParseConstants.KEY_SENDER_NAME));

This error isn't happening when the inbox fragment initially loads, nor when returning from viewing an image.

Here is my InboxFragment on resume method:

@Override public void onResume() { super.onResume(); getActivity().setProgressBarIndeterminateVisibility(true); ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(ParseConstants.CLASS_MESSAGES); query.whereEqualTo(ParseConstants.KEY_RECIPIENT_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) {
                //success... 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);

            }
        }
    });
}