I also noticed that a normal non-administrator user is not even able to change the language anymore:
If I do the change within the foxit UI, it requires me to enter administrative credentials to do the change, eventhough the necessary language files in the program files folder are already present.
Apparently it creates an updater process, which needs to alter something in the system?
When a change to the default English is done, no administrative credentials are necessary.
I didn't find the right solution from the Internet.
References: http://forums.foxitsoftware.com/forum/p ... e-languageExplainer Video