Upcoming ION hard fork introduces new version of zerocoin protocol, xION v2. New version uses different protocol for recording and accessing xION. "Old" version is associated with the wallet.dat file, v2 introduces seed, which is the portable passphrase. Also, v2 xION allows earning stakes and is great for private voting.
The update will occur in three phases:
1. Release of the new ION client, by January 31st. Users will be able to sync and receive transactions but until they upgrade, they won't be able to create new ones.
2. Maintenance mode. On February 7th ION will go into maintanace and between February 7th and February 10th users won't be able to mint or spend new v1 xION.
3. xION v2 go live. The upgrade will be completed by February 10th. Users will be able to mint, stake and spend xION v2 and spend xION v1.
During the transition period all v1 xION functions will be paused. ION users should spend all v1 xION before they will update wallets and of course, make a backup before upgrade!
Upcoming ION hard fork introduces Version Two of zerocoin protocol (xION v2). Before you upgrade to new wallet: 1)Turn off zerocoin minting and 2) Spend all your Version One zerocoin (xION v1).https://t.co/zknK1Tqt7N— ionomy (@ionomics) January 27, 2019
Why you should spend all your xION before update? How to spend it? Answer for these questions and more details about the update you can find in the official announcemet