Over the weekend, Red Dead Redemption and some other Xbox 360 games became playable on Xbox One, despite not being announced as titles joining the backwards compatibility lineup. Now, Microsoft has explained that these games were made available publicly "due to an error" and have since been completely removed.

"Microsoft tests all Xbox 360 games with our [backwards compatibility] emulator to ensure a quality experience across a breadth of titles," Microsoft's Larry "Major Nelson" Hryb said on Reddit. "Due to an error, some of the games currently in test were accidentally made available. We have since removed access to those games, and apologize for any confusion this may have caused. We will have more information on upcoming releases soon."

Hryb apologized a second time on Twitter.

On Saturday, February 6, people started to discover they could download Red Dead Redemption (as well as Left 4 Dead 2 and others) through a number of methods. However, a day later, Red Dead Redemption became unplayable and Microsoft even warned playing it could be a violation of Xbox Live's Code of Conduct.

People who downloaded Red Dead Redemption before it was removed reported that, while they can no longer play online (the game requires an update that cannot be installed, they say), it remains playable offline. However, players say game saves are unavailable offline, which is quite a problem for such an expansive game.

According to some people who played Red Dead Redemption on Xbox One, the 2010 open-world western performed well from a technical perspective. Microsoft has said it is in discussions with Rockstar about bringing Red Dead Redemption to Xbox One, but from the sound of Microsoft's statement, it appears the company was independently testing the game.

For now, you can check out the list of the 130 games in the Xbox One backwards compatibility program.