A couple of hours before the the ZenCash launch this was posted in the Zen slack:
blockops [2:59 PM]
7 Day Delay in ZenCash LaunchDuring extensive testing of the ZenCash node software prior to launch our developers identified an intermittent issue with transaction completion. Some of the transactions completed successfully on the testnet, and others did not.
Through working to identify the issue they discovered that one of the changes made to prevent transaction replay between the ZenCash and Zclassic blockchains caused the problem.
The code changes required to fix the intermittent issue are extensive and require more time than we have before launch tonight.
Because of this issue, the ZenCash core team decided to delay the launch by 7 days, to May 30th. This decision was not made lightly, but due to the nature of the launch, where 1,375,000 ZenCash tokens will immediately come into existance, we decided it was more important to be 100% certain the ZenCash blockchain, node software, and wallets are working properly before launch.
Thank you very much to the ZenCash community developers who have worked diligently these last few days to troubleshoot and identify the issue.
Thank you to everyone that has supporting ZenCash so far, and we look forward to a launch in 7 days.
Also this was said:
movrcx [2:50 PM]
heads up all we’re going to need to delay the mainnet launch about a week due to some issues we discovered with testnet and rewarding zcl holders while still maintaining transaction replay protection.we’ve got some good news that we’ll announce later on tonight though to compensate. :wink: @blockops is working on writing up an annoucement.
jeffrey [2:51 PM]
So trading on Bittrex will still be closed?movrcx [2:52 PM]
Yes we’re contacting Bittrex now @jeffrey and will do.
It is unclear if the partnership that will be announced is directly related to Zen or if it will confirm the rumors about a second Zclassic fork.