Owners of the Oculus Rift VR headsets who tried to play a game yesterday found that the headsets weren’t working. The reason for the non-functioning devices was unknown at the time. The error that users were seeing on their headsets stated, “Can’t Reach Oculus Runtime Service.” Oculus admitted there was an issue not long after complaints started

Source: Hot Hardware – Oculus Rift Headsets Are Working Again Following Unexpected Downtime