ConnectPort X2 Radio Module Firmware Update

I tried updating the firmware on the ConnectPort X2 radio module by removing the radio module and connecting it to X-CTU (using an X-BIB). The module works fine in X-CTU and I can connect to remote modules, but unfortunately the Gateway won’t recognize it anymore. When I connect to the Gateway and go to XBee Network > XBee Devices, I get the following error:

“The XBee Network is not available - the gateway radio is currently configured for serial access from a legacy application.”

Is there a configuration setting I need to change in the XBee module?