If your Axe Fx II XL goes bonkers after attempting a firmware update, this is your solution:
http://support.fractalaudio.com/index.php?/Knowledgebase/Article/View/15/4/axe-fx-ii-xl-failsafe-firmware-recovery
http://support.fractalaudio.com/index.php?/Knowledgebase/Article/View/15/4/axe-fx-ii-xl-failsafe-firmware-recovery