You have 3 alternatives for a missing menu item, while clicking to change language
- Disable Joomla language switcher / filtering
... if you do not have a multi-language site or if you have a 3rd party tool to use as language switcher
- Set the language of your menu items to "ALL"
- For every missing menu item:
Create (inside a different menu) and the menu item that has the missing language e.g. "German" language, and then associate it with menu item of the menu item that exists already e.g. "English" language menu item
HOW TO avoid having INACCESSIBLE menu items:
- Do not place a menu item under a parent menu item that is of different language, e.g. do not place English menu item, under German menu item, [b]but you can place a English menu item under a menu item with language ALL
- Avoid placing a menu item under a menu item of different access level,
-- e.g. a public menu item under a "non-public" menu item, because it will not be accessible to guest user and will give you an error !!
-- and usually this is not what you want
-- ... all access levels of parent menu items are required in order a user to be able to view the final menu item
ALSO please read this FAQ article:
Using language switching for menus / categories / items