Fan Speed Not Supported

I started using the Razer Fan Controller. I have several fans. 4 of the fans are the EK-Vardar EVO 120ER Black BB. 2 of the 4 fans worked fine but the other 2 came up with the error of "fan speed not supported." I cannot adjust or view their speed but they are spinning. After 2 weeks, the other 2 fans started giving the "fan speed not supported" error. What causes this? Is there something I need to do to get the controller to recognize them? They were controllable with my motherboard prior to installing the Razer Controller.