@u50623 - Here is part an explanation and apology I just posted to our blog, http://lingqcentral-en.lingq.com/.
We would like to apologize for the extended outage of LingQ which happened earlier today. This outage was the result of an unexpected failure of one of our database components. This caused some data to be corrupted and required that data be re-processed in order to restore its original condition. Unfortunately this process proved to be quite time consuming. On top of it all, the issue arose while LingQ Vancouver technical personnel were in bed. We became aware of the issue at 5:30 this morning, whereupon our technical team began working to identify and fix the issue.