This happens when you try to run the game on PC and connect the headset via USB cable or using air link. Right now, Oculus software does not read the guardian info properly (read: doesn't read at all and provides whatever was set before for other headset, like Rift, or nothing).
I really do hope that Oculus will sort it out soon. For my game I'm fine with adding "calibration" tool. But other games that do not support that might be unplayable (unless you're lucky with the play area and you already set it for Rift and you stand exactly in the middle, facing the right direction and then you connect to PC).