Rebellion has apologised for problems affecting matchmaking on the PC and PS3 versions of the Aliens vs. Predator demo released yesterday.
While the Xbox 360 version was not affected, PC owners had issues joining games until a Steam patch was issued later in the day, and PS3 problems may be ongoing - Rebellion has said it's investigating reports.
"The full game features the ability to browse for and create games but for the purposes of simplicity the demo was limited to matchmaking, alongside the ability to set up groups with friends which mitigated yesterday's issues for many.
"We're really sorry that this issue tainted a day in which we saw many people get hands-on with AVP for the first time and we're hugely gratified by the positive feedback to the game."