This version is incompatible with the 6.14 version of Drupal core.

I created a module and put the following code in it. However, when I tried to activate the module it is giving this error message.

"This version is incompatible with the 6.14 version of Drupal core."

Here is the code:

<?php
// $Id$
/**
* @file
* Implements various blocks
*/
/**
* Implementation of hook_block().
*/
function approval_block($op = 'list' , $delta = 0, $edit = array()) {
switch ($op) {
case 'list':
$blocks[0]['info'] = t('Yahoo Rank');
$blocks[0]['cache'] = BLOCK_NO_CACHE;
return $blocks;
}
}

Please let me know what I am missing.

Thank you,