Error: Exception printing is disabled by default for security reasons

Sometimes you will get the following error when accessing Magento sites:

~~~~~
There has been an error processing your request
Exception printing is disabled by default for security reasons
Error log record number: XXXXXXXXXXXXXXX
~~~~~

This point, you should check the error report that was generated. Magento 1.4.0.1 additional security enhancements which is why you see Exception
printing is disabled by default for security reasons. Instead you
need to go and look at the error report which can be found in
var/reports/{report_id} in the Magento installation directory.
Eg:
/home/test/public_html/var/reports/533022418847

Here is the solution:

1. Navigate to the "errors" folder.
2. Change local.xml.sample to local.xml
You should now see a new list of crazy errors all over the Magento page - this is okay.
3. Open magento/lib/Zend/Cache/Backend/File.php and look for:
protected $_options = array(
'cache_dir' => 'null',
Change it to:
protected $_options = array(
'cache_dir' => 'tmp/',
4. Save it.
5. Now the final step is to go create a tmp folder in the root Magento folder.
That's it.