Bittrex email response:
"Unfortunately, we found an unexpected incompatibility between our deposit smart contracts and the MGO token contract. Anyone who attempted to send token to us had their transaction cancelled by the MGO contract. We do not hold these coins as they would never have been sent. We regretfully will be suspending the launch of MGO Trading.
If you have sent MGO to a waves address please be aware we do not support this transactions and will be unable to recove these coins at this time.
Thank you,
Ryan @ Bittrex "