When I open LingQ, it loads to a page with four tabs: Library, My Lessons, Vocabulary, Playlist. This Vocabulary tab does not work. To get into Vocabulary, my current fix is: click on Lessons (note: Lessons, not My Lessons) in the top left, at which point a new screen opens with six links in two rows of three - Lessons, Tutors, Community/Library, Playlists, Vocabulary. This Vocabulary link does work.
Actually you should only see Library Playlist and Vocabulary options at the top left. My Lessons do not exist anymore. It sounds like you are using old website version somehow. Can you take a screenshot of what you see and send it to support(at)lingq.com? Thanks!