CVar checkAddonVersion

Controls whether out-of-date addons (those with non-current Interface: .toc tag) are loaded.
 
==Default Setting==
;1
==Possible Settings==
;0 :Out of date addons are loaded
;1 :Out of date addons are not loaded
==Changing this setting==
In-game, type the following
 /console checkAddonVersion setting
Alternatively, you can exit wow, open the Config-cache.wtf file, and add the following line:
 SET checkAddonVersion setting