Because ZEC is undergoing system upgrade, Huobi pro will suspend ZEC withdrawal between 14:00 Mar 13th to 14:00 Mar 14th. Deposit will not be affected except that the credit time may be delayed. We apologize for the incovenience that this may cause. Thank you for your understanding.
The official announcement of ZEC: https://blog.z.cash/overwinter/
March 13, 2018