I just noticed that when using the plex web interface, if you go to 'Settings' -> 'Server' -> 'Languages', you end up at 'Settings' -> 'Server' -> 'General'. So either the 'Languages' section should not exist, or it should have it own page again. :)
I am running the server on Linux and have verified this problem with version 1.1.3.2700-6f64a8d and 1.2.0.2716-837790c.