Zcash activated a major network upgrade on June 3 that briefly caused block explorers to show no new blocks. Developers also suspended Orchard transactions to fix a privacy pool bug.
The Zcash blockchain upgrade took place at block 3,364,600. Many block explorers failed to update their nodes immediately, creating the appearance that no new blocks were produced for more than four hours after 5:27 AM UTC. Josh Swihart, CEO of ZODL, said the issue stemmed from explorers still watching the old chain while miners moved to the upgraded version. Mert Mumtaz of Helius confirmed the same explanation. Separately, Zcash developers paused Orchard transactions to address a vulnerability that could have allowed double-spending in the privacy pool. No exploitation occurred. ZEC rose 8 percent over the past week and 46 percent over the past month.
