Some Syndicate players have complained of game freezes, particularly on the Xbox 360. EA tells Shacknews the team is working on the problem, but in the meantime it offers a quick fix users can take to mitigate the issue.
The complaints began to appear on the EA Forums once the game launched. The problem seems relatively rare, with only a handful of players lodging complaints, but their information is fairly uniform. It usually strikes the Xbox 360, during co-op matches.
Shacknews contacted EA, and received this response: "If you're experiencing freezing during a multiplayer match this may be due to a conflict between XBL Party Chat and the default in-game chat. We've sent this issue on to the team and they will look further into it, but in the meantime try jumping out of your Party Chat and using the in-game channel to see if this fixes the issue."
If you've experienced the bug on any platform, giving EA more feedback on its forums will help give the information they need to fix it. In the meantime, it sounds like an easy enough problem to avoid if Party Chat is to blame.