Error in plugin.php – Showing blank dashboard

My Dashboard is blank from Dashboard all the way to Settings. I can see the menu on the left hand side, but when I click on Pages / Posts etc it is blank. I get the following error showing when I define(‘WP_DEBUG’, true);

Notice: Undefined offset: 0 in web/wp-includes/plugin.php on line 764 Notice: Undefined offset: 0 in /web/wp-includes/plugin.php on line 782

It is referring to this function:

function _wp_filter_build_unique_id($tag, $function, $priority) {
global $wp_filter;
static $filter_id_count = 0;

if ( is_string($function) )
return $function;

if ( is_object($function) ) {
// Closures are currently implemented as objects
$function = array( $function, ” );
} else {
$function = (array) $function;
}

if (is_object($function[0]) ) {
// Object Class Calling
if ( function_exists(‘spl_object_hash’) ) {
return spl_object_hash($function[0]) . $function[1];
} else {
$obj_idx = get_class($function[0]).$function[1];
if ( !isset($function[0]->wp_filter_id) ) {
if ( false === $priority )
return false;
$obj_idx .= isset($wp_filter[$tag][$priority]) ? count((array)$wp_filter[$tag][$priority]) : $filter_id_count;
$function[0]->wp_filter_id = $filter_id_count;
++$filter_id_count;
} else {
$obj_idx .= $function[0]->wp_filter_id;
}

return $obj_idx;
}
} else if ( is_string($function[0]) ) {
// Static Calling
return $function[0] . ‘::’ . $function[1];
}
}

LINE 764 is: if (is_object($function[0]) ) {

LINE 782 is: } else if ( is_string($function[0]) ) {

I don’t know how to fix the code. Any ideas?

Many thanks
Simone