If you are using W3C, try removing all traces of it (temporarily) and see if that addresses anything. If that did solve the problem, try re-installing W3C, as maybe one or more of its files went missing or got corrupted (or perhaps you didn’t link your account correctly).
But there are multiple other causes of being stuck at the lion screen or the black screen afterward. There are some connection related issues, though these will usually stop you at the lions gate rather than a black screen.