A currency exploit in the Neverwinter beta forced Perfect World Entertainment to go back in (virtual) time, erasing seven hours of player data. The exploit had allowed some unscrupulous folks to gain billions in Astral Diamonds.
Polygon reports that the bug was discovered early on Sunday, and the servers were taken down in the afternoon. All progress made between 8:20 AM and 3:20 PM ET was erased. The bug has been fixed, and Perfect World says it has taken actions against the exploiters. The Auction House and Astral Diamond exchange are inactive for the time being, and will undergo testing before being put back up. The publisher is planning gifts for players to thank them for bearing with the inconvenience.
"Rather than let the malicious efforts of a few unsavory players linger and continually impact the game's economy and balance as we progress through these later stages of Open Beta, we have made the extremely difficult decision to rollback Neverwinter to a time shortly before the abuse and exploitation began," read a post on the Perfect World forums.