It seems you didn't configured the basedir path in your config.php

Put the complete unix path to 'public_html' folder in basedir field.

To get the unix path to public_html go through

http://yourdomainname.com/phpinfo.php

And search for 'SCRIPT_FILENAME' then you can see the complete unix path to the phpinfo.php

It will be something similar to '/home/username/public_html/'

$config['basedir'] = "/home/username/public_html/";

And try again.

Also the baseurl you given in the config.php file is not working for me.

If you can provide the actual url, i can give the exact path.