With AccessControl extension, Special:Version yields:
/index.php/Special:Version MWException from line 121 of includes/page/WikiPage.php: Invalid or virtual namespace -1 given. Backtrace: #0 extensions/AccessControl/AccessControl.hooks.php(86): WikiPage::factory(Title) #1 extensions/AccessControl/AccessControl.hooks.php(294): AccessControlHooks::getContentPage(integer, string) #2 includes/Hooks.php(177): AccessControlHooks::onUserCan(Title, User, string, string) #3 includes/Hooks.php(205): Hooks::callHook(string, array, array, NULL) #4 includes/Title.php(2269): Hooks::run(string, array) #5 includes/Title.php(2734): Title->checkPermissionHooks(string, User, array, string, boolean) #6 includes/Title.php(2135): Title->getUserPermissionsErrorsInternal(string, User, string) #7 includes/MediaWiki.php(207): Title->getUserPermissionsErrors(string, User) #8 includes/MediaWiki.php(863): MediaWiki->performRequest() #9 includes/MediaWiki.php(524): MediaWiki->main() #10 index.php(42): MediaWiki->run() #11 {main}
Or in short, it does not support Special pages which have namespace value of -1 (NS_SPECIAL).