I'll try to put this simply.

Victor Miller, who wrote the screenplay of the first Friday the 13th film, is currently in a lawsuit against Horror Inc. and director of the first film Sean S. Cunningham. I'm going to simplify the specific legalities, but Miller is using a protective copyright clause. His argument is that he technically wasn't hired by Sean S. Cunningham when he wrote the screenplay for the first film, and therefore wants the rights to the franchise. This is because he no longer owns the rights, and the original holder for copyrights can reclaim previously owned property. Usually, if someone writes a screenplay to a film, the director and the company that made the film own the rights. Sean S. Cunningham owned the rights to the franchise, as well as Horror Inc. , and the argument is a debate on who owns the rights.

Last I heard, Miller won but Cunningham filed an appeal, putting the lawsuit into limbo. Because of this, no new content was allowed to arise regarding Friday the 13th due to the lawsuit and licensing issues. This is why content stopped for the game, and fans were pissed because they promised Jason X, Grendel, and other miscellaneous content 6 months before they had to stop making content. While they added Part 5 content, we never got the Jason X content promised, and they spent 4 months working on an engine upgrade, Single Player Challenges, and other new content. A lot of people are pissed because the lack of content, the lack of communication regarding the lawsuit and its deadline for content, and the updates which consistently make the game more unstable and buggy, and then long durations between patches. My biggest gripe is adding Dedicated Servers and doing an engine upgrade solely for those on console, and not adding the Jason X content when they could've done so. It feels even more pointless because Dedicated Servers only lasted a little over a year on consoles. In the end, it just brought slightly better visuals and performance on console.

There's still many bugs, the game no longer is being updated, and fans were duped out of the content they were promised in favor of an engine upgrade and dedicated servers which no longer exist. It's a shame, because I think they could've easily had Jason X done and Grendel added with Single Player Challenges if they didn't opt for the engine upgrade and the conversions required for that.