Hi,
I just was at the last level for my Vangaurd.. and it randomly kicks me out at the end..
Probaly wasting all my sparks and loot etc.
Error Message;
We experienced a problem authenticating with Steam. Please ensure that the Steam client is running and that you are not logged in elsewhere.
Very easy, I use two monitors.. Nothing wrong with Steam, Steam been online the whole time, only SK gives me that Error Message constantly.
Please fix as soon as possible!
Yours faithfully,
Violence.
Is this an ongoing issue for you? Going by the Steam Stats page it looks like there was a minor service interruption on Steam right around the same time you posted this thread.