The Item Hoppers on survival are not responding. People said that they removed the code the way hoppers work, due to there are different duplication glitches, maybe there is a way how to remove it the glitches on duplicating, just please do not remove hoppers, because it lessens the way how redstone and xp grinders others, work. If not. Please help me on forums/ In-game how can I make my grinder work please :> ~Bae
The hoppers won't be returned to its former state(as of now). Maybe just throw it in chests after you kill the mobs for loot? No other way I can help :/
Hello! Hoppers have been disabled on other servers as well and others are awaiting for them to return. Here's a quote from CypriotMerks about them: "It's not broken, we added a small plugin (Thanks to TannerLittle) to stop a duplication glitch." I hope this information helps. Basically there's a dupe glitch and hoppers are on there way back into the game. Cheers, Gizz.
For any further updates and more info, please refer to http://www.mineverse.com/threads/hoppers.50734/#post-516922