Fatal error: main(): Failed opening required ''

[marcan]

Hi,

I created a task in an opportunity and assigned it to another employee. When I clicked on the create button, I got this fatal error :

Fatal error: main(): Failed opening required '' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/inboxfac/public_html/crm/index.php on line 579

The URL was :

http://sugarcrm_path/index.php?modul...odule=Contacts

I'm using SugarCRM 4.5.1 RC on PHP 4.4.

What can I do to fix this problem ?

Thanks !