Who knows that why the bittrex can't Withdrawal or Deposit SUM ? 
i can withdraw and deposit yesterday. What error u got ?
I can withdraw and deposit yesterday too.
The Bittrex.com can't Withdrawal or Deposit SUM . It's now!
maybe u can contact support. They usually response within couple of hours. Btw, I was able to withdraw SUM from pholoniex few hours ago and receive it in my wallet within 10 mins of withdrawal