Hi
a) First step would be to turn debugging on in config.php
// @error_reporting(E_ALL | E_STRICT); // NOT FOR PRODUCTION SERVERS!or ../admin/settings.php?section=debugging
// @ini_set('display_errors', '1'); // NOT FOR PRODUCTION SERVERS!
// $CFG->debug = (E_ALL | E_STRICT); // === DEBUG_DEVELOPER - NOT FOR PRODUCTION SERVERS!
// $CFG->debugdisplay = 1; // NOT FOR PRODUCTION SERVERS!
b) second step : check errors in page or apache error log.
Let us know!
Regards