According to the Horizen (ZEN) team, a mandatory ZEN upgrade will take place at block# 1027500, estimated on Oct 27 06:00-10:00 UTC. Gate.io supports this upgrade and will suspend Horizen (ZEN) deposits and withdrawals during the process. Deposits and withdrawals will be resumed as soon as possible after this upgrade. ZEN trading will not be affected.
Thank you for your understanding and continued support.

The ZEN 2.0.24 release is an interim update in preparation for the next release supporting Zendoo-Horizen’s sidechain and scaling solution, which is now available at github

Learn more:
https://blog.horizen.io/mandatory-software-upgrade-zen-2-0-24-coming-soon/