"There has been an error processing your request" error in Magento

When I logged in to the admin panel or open base url of magento site (http://www.example.com/admin or http://www.example.com/). I got this wierd looking page on my screen.

I googled this "There has been an error processing your request" and found the solution as follows-

1.   Open Magento root directory and create tmp folder.

2.   Set directory permissions to 777 or 755

3.   Open "lib/Zend/Cache/Backend/File.php"

4.   locate the following code:

              protected $_options = array(
                     'cache_dir' => null,

                           and replace with

                 protected $_options = array(
                       'cache_dir' => 'tmp',

Reference: 

http://stackoverflow.com/questions/15473705/there-has-been-an-error-processing-your-request-error-log-record-number

http://magento.stackexchange.com/questions/8905/there-has-been-an-error-processing-your-request
        

Best Wishes!!!