"Duplicate withdrawal information" error for address description

The "Duplicate Withdrawal Information" error occurs when you try to add a new withdrawal address with the same description as an existing withdrawal address on your account.

All withdrawal addresses on your account must have a unique description; you cannot use the same description even if it is for two different cryptocurrencies.

For example: If you have a Bitcoin (XBT) withdrawal address called "My vault", you cannot add another withdrawal address for Ethereum (ETH) also called "My vault". 

Instead, you'll have to use descriptions such as "My Bitcoin vault" and "My Ethereum vault".