android AsyncTask Class cast exception

Trying to use AsyncTask for logging in user to parse.com before proceeding. Am getting a class cast exception.

Relevant Code:

package com.simoyi.chatabout;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.database.Cursor;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.parse.ParseAnalytics;
import com.parse.ParseUser;


public class GroupsActivity extends Activity {

private static Cursor result;
private static SimpleCursorAdapter adapter;
private Context context;

private ListView lv;
private ProgressDialog prgDialog;
private TextView txt;
private CheckAuthD check;
private TextView b;

/**
 * *****************************************************************************************************
 */

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

    b = (TextView) findViewById(R.id.text4);

    context = this;
    ParseAnalytics.trackAppOpened(getIntent());
    checkAuth();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_groups, menu);
    return 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.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

/**
 * *****************************************************************************************************
 */

public void checkAuth() {
    if (ParseUser.getCurrentUser() != null) {
        initializeViews();
    } else {
        AsyncTask load = new checkForAuth();
        load.execute();
    }
}

public void getLoadResult(String result) {
    /*
    check.dieDdie();
    if(result){
        checkAuth();
    }
    else{
        Intent intent = new Intent(this, SignUpActivity.class);
        startActivity(intent);
    }
    */
    check.dieDdie();
    TextView a = new TextView(this);
    a.setText(result);
    setContentView(a);
}

public void initializeViews() {
    try {
        lv = (ListView) findViewById(R.id.groups);
        Utility u = new Utility(context);
        result = u.getJoinedGroups();
        adapter = new SimpleCursorAdapter(this,
                android.R.layout.simple_list_item_2,
                result,
                new String[]{"groupName", "desc"},
                new int[]{android.R.id.text1, android.R.id.text2});
        lv.setAdapter(adapter);
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {

                // selected item
                String selected = ((TextView) view.findViewById(android.R.id.text1)).getText().toString();

                Toast toast = Toast.makeText(getApplicationContext(), selected, Toast.LENGTH_SHORT);
                toast.show();

            }
        });
    } catch (Exception ex) {
        Toast toast = Toast.makeText(getApplicationContext(), ex.getMessage(), Toast.LENGTH_SHORT);
        toast.show();
    }
}

/*
public void showCheckDialoga() {
    FragmentManager fm = getSupportFragmentManager();
    check = new CheckAuthD();
    check.show(fm, "dialog");
    txt = (TextView) findViewById(R.id.loading);
}
*/

public void updateDialoga(String update) {
    txt.setText(update + "\n" + "Loading...");
}

/**
 * ******************************************************************************************************************
 */

private class checkForAuth extends AsyncTask<String, String, String> {

    GroupsActivity act;
    Context context;
    String result;

/*
public checkForAuth(GroupsActivity a){
    act = a;
    context = a;
}
*/

    @Override
    protected void onPreExecute() {
        //act.showCheckDialoga();
        b.setText("Beginning");
    }

    @Override
    protected String doInBackground(String... params) {
        try {
            Account account = new Account(context);
            if (account.checkForUsername()) {
                publishProgress("Identified user account...");
                account.logIn();
                publishProgress("Account logged In...");
                result = "yes";
            } else {
                result = "no";
            }
        } catch (Exception e) {
            e.printStackTrace();
            result = e.getMessage();
        }
        return result;
    }

    protected void onProgressUpdate(String... progress) {
        //act.updateDialoga(progress[0]);
        b.setText(progress[0]);
    }

    @Override
    protected void onPostExecute(String result) {
        //act.getLoadResult(result);
        b.setText(result);
    }
}
}

LOGCAT:

--------- beginning of crash
04-19 11:09:42.108    2473-2505/com.simoyi.chatabout     E/AndroidRuntime﹕     FATAL EXCEPTION: AsyncTask #1
Process: com.simoyi.chatabout, PID: 2473
java.lang.RuntimeException: An error occured while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:300)
        at     java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
        at     java.util.concurrent.FutureTask.setException(FutureTask.java:222)
        at java.util.concurrent.FutureTask.run(FutureTask.java:242)
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
        at     java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
        at     java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
        at java.lang.Thread.run(Thread.java:818)
 Caused by: java.lang.ClassCastException: java.lang.Object[] cannot be cast to java.lang.String[]
        at com.simoyi.chatabout.checkForAuth.doInBackground(GroupsActivity.java:139)
        at android.os.AsyncTask$2.call(AsyncTask.java:288)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:818)

What could be the problem?