I’ve tried to open several lessons and all of them error out with “There was an error opening this lesson. We have been notified and will investigate this issue. You will be redirected to the home page where you can try opening another lesson.” even ones that I’ve already worked through and completed like German LingQ Podcast 1.0, #21 Anke & Vera - Planning a Ho... so something’s very off… Am using Safari Version 10.1.1 (12603.2.4) in MacOS Sierra if that helps.
Hope you can fix it soon. Otherwise keep up the good work.