Microsoft has ordered a mod team to stop work on a Halo: Online modification that essentially allowed users to play Halo 3 multiplayer matches on PC. The mod itself is an effort by the ElDewrito team to create a workable and feature-rich Halo game for Windows. It has been in development since official work on Halo: Online, a Russian-only port of Halo 3’s online offerings, was halted in 2016.

While they didn’t send a cease-and-desist letter to the creators, they did inform them that they should stop work on the mod while the publisher investigates further to make sure its intellectual property it not being misused.

“While we are humbled and inspired to see the amount of passion poured into this project, the fact remains that it’s built upon Microsoft-owned assets that were never lawfully released or authorised for this purpose,” 343 said in a statement.

“As this project reverberated across the community, our team took a step back to assess the materials and explore possible avenues, while Microsoft, like any company, has a responsibility to protect its IP, code and trademarks. It’s not optional in other words.”

However, Microsoft have issued takedown notices on streaming sites like Twitch and YouTube for those broadcasting Halo: Online games. This has resulted in footage being removed and streamers being banned for 24 hours. 343 employees have suggested users title their streams without mentioned Halo: Online specifically as they are likely being caught up in automatic DMCA requests.

It looks as if Microsoft and 343 Industries may be working to bring more Halo content to PC platforms. Head of Xbox Phil Spencer even suggested they could work with mod creators directly to bring the franchise to a wider audience in the future.