Skill Tree Frozen :((
My skill tree is frozen, I have completed Adj 1. and translated many articles trying to get it going again, but I cannot unlock any further levels. I have restarted browser, computer, cleared cookies etc, all to no avail.
I love Doulingo but have found it "klugey". Lot's of things don't work seamlessly. Make certain you have the latest fixes of your operating system and browser. If that doesn't help try another browser. I have found some things that don't work in IE work in Crome or Mozilla. It's free and for me much more fun than Rosetta Stone.
I had this problem a couple of hours ago, it has now fixed though so you probably just have to wait for it to catch up!