We are aware of an issue that is currently affecting some new WordPress installations.
If you have tried to install WordPress recently and after installation, error messages relating to cache.php and an 'Illegal Offset' appear we have the following workaround for you:
Edit /wp-includes/plugin.php [Line : 102], inside remove_filter function.
Change :
unset($GLOBALS['wp_filter'][$tag][$priority][serialize($function_to_remove)]);
To :
$wp_filter[$tag][$priority][serialize($function_to_remove)] = array();
unset( $wp_filter[$tag][$priority][serialize($function_to_remove)] );
After making the above change all the problems should be fixed and the error messages should disappear.
Please remember to make a backup of your original plugin.php file before making the above amendments.If you need any help with this, please let us know.