after installing MC on my site, i got the following fatal error: Fatal error:
Call to undefined function mb_eregi() in /mnt/webc/22/79/52671079/htdocs/wsc/administrator/templates/rt_missioncontrol_j15/lib/phpQuery.php on line 1421
your PHP does not have the required mb_eregi() method compiled in. You should contact your hosting provider about this as it's a standard function in PHP. However, to get your backedn back, just rename rt_missioncontrol_j15 to something else, eg rt_missioncontrol_j15.backup and it will revert to the standard template.