Try harder to write the code. Simple

warning: your solution setup isn't functionnal: you put a char as output instead of a String. ;) Note that you could have separate the random tests from the first method, but no problem with that.

Many people had such problems yesterday (and it seems to be happening now as well). It's most probably a problem with their servers. They should fix it in a couple of days, at least I think so.

Yes, it is a server problem. Also your own solutions doesn't show in Solutions tab of a kata after you've succesfully submited them (but you can still see them in your profile, at least I noticed that too). I think it'll be solved eventually.