Exchange Bitstamp and KuCoin temporarily suspended Ethereum's withdrawal due to congestion and instability of the network. KuCoin even recommended that users use NEO instead of Ethereum in order to have "permanent access to their means". This is reported by Bitcoin.com.
In recent months, the network Ethereum has experienced a sharp increase in user activity. According to etherscan.io, in October 2017 the number of transactions in the network did not exceed 519,000 per day, however, on January 4 this figure was already 1.34 million.
We've detected the network congestion of ETH official website, it is more likely the occurrence of delay withdrawal of ETH from part of the users. Hence we'd recommend users to proceed withdrawal by transferring ETH to NEO. pic.twitter.com/Fij9AuPJB0
— KUCOIN (@kucoincom) 17 января 2018 г.
Thus, the instability of the network was significantly exacerbated by the launch of the game CryptoKitties, to which users showed increased interest. In connection with this, the fees for transfers significantly increased, and many transactions were suspended for several days.
The European exchange, Bitstamp, suspended Ethereum's withdrawal for several hours, but soon notified the users about the successful resolution of the problem.
RESOLVED: The issue with ETH withdrawals has been fixed. We will continue to monitor the situation. Thank you for your understanding and patience.
— Bitstamp (@Bitstamp) 17 января 2018 г.
Representatives of the KuCoin Exchange also reported on the congestion of the Ethereum network and possible delays with the withdrawal of ETH, advising users to use NEO crypto currency, also known as "Chinese Ethereum", as an alternative. In addition, users were warned about the high risks of trading in the current volatility.