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There is a major item-duplication bug in Diablo 4 right now, one that has forced Blizzard to disable all trading in its ARPG as it investigates the issue.

As spotted by Diablo content creator Rob2628, a duplication bug seemingly introduced as part of Season 5 was highlighted in a recent stream on Chinese video platform bilibili. Players were shown duplicating some of Diablo 4's best items and most sought-after materials.

There is a massive duplication exploit going on in #DiabloIV right now. Trading of any kind has been disabled as thousands of dupes materials are flooding the market.
There apparently has been a stream in China where the duplication exploit has been shared publicly to thousands… pic.twitter.com/OisZzHvTjQ

— Rob2628 (@Rob_2628) August 14, 2024

Images from the stream show players with inventories full of Mythic Unique items like Harlequin Crest and thousands upon thousands of Stygian Stones, a material needed to summon Diablo 4's most difficult (and most rewarding) bosses. Just a few months ago, a small stack of Stygian Stones would sell for dozens or hundreds of millions of gold, but a look at Diablo trading websites reveal players selling hundreds or even thousands of the boss-summoning materials for just a few million gold, as duplicated items look to have started hitting the market more widely.

Diablo community manager Adam "PezRadar" Fletcher in a forum post stated Blizzard has disabled trading in Diablo 4 entirely as knowledge about the exploit spreads.

"We apologize for the disruption and will provide updates on when we will have trading available again once we further investigate and identify any issues we need to resolve," Fletcher said.

This isn't the first time Diablo 4 has been affected by an item-duplication bug (players have been duping items since the Diablo 2 days, after all), but it does seem to be one of the more serious instances, especially given how widespread information about it appears to be in China. Blizzard allowed players to trade Unique and Legendary items starting with Diablo 4's Loot Reborn update earlier this year. However, Mythic Uniques, the game's very best items, are still not tradeable.

Diablo 4 Season 5 introduced a new endgame activity, the Infernal Hordes, as well as massively improving all of the game's Unique items to make them more sought-after for endgame builds. Blizzard has released three hotfixes for Season 5 so far, including making it so guaranteed sources of greater affix items are now actually guaranteed as intended.

Vessel of Hatred, Diablo 4's first expansion, will release on October 8. It will introduce a new class to the franchise, the Spiritborn.

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