Tomorrow, Thursday May 10th 2018, we will upgrade our Bitcoin wallet infrastructure to be fully SegWit compatible. Unfortunately, this requires that all deposit addresses will change and transactions to old addresses will no longer be credited. If you send funds to and old address by accident, we will manually credit your deposit upon your request.
SegWit, among other things, increases the available space for transactions per block and makes second-layer solutions, like the Lightning network, possible.
After this upgrade it will also be possible to send Bitcoin transactions to the new alternative address format called Bech32.