The message indicates that you have a pre-production CX phone, verified by the Rev.X (e.g. Rev.X10) hardware revision (marking found on the bottom of the phone). These were only passed out as demo units prior to their official release. A production model is defined as with Rev. A, B, C, etc code.
Unfortunately these are pre-production devices and should not be used in the field. In CU2 Microsoft started blocking all pre-production devices by displaying this message in the firmware, and you cannot roll the device back. You'll need to swap the devices out with an actual production unit.