Error in includes/function
 

I'm currently trying to fix my site forum by myself.

I followed the instruction on this thread -
http://www.vbulletin.com/forum/showthread.php?t=297299

and did this -

5.You might also need to set the MySQL charset in your includes/config.php file by uncommenting this line. This setting was added starting with 3.5.x:

Code:
// ****** MySQLI OPTIONS *****
// When using MySQL 4.1+, MySQLi should be used to connect to the database.
// If you need to set the default connection charset because your database
// is using a charset other than latin1, you can set the charset here.
// If you don't set the charset to be the same as your database, you
// may receive collation errors. Ignore this setting unless you
// are sure you need to use it.
// $config['Mysqli']['charset'] = 'utf8';
_____

And now, I'm getting this error when trying to access my forum and ACP :

Warning: array_keys() [function.array-keys]: The first argument should be an array in [path]/includes/functions.php on line 4227

Warning: Invalid argument supplied for foreach() in [path]/includes/functions.php on line 4227

Please help. Thanks.