Q: SMS message are not loading just showing a blank screen?? using an iphone 6 IOS 9

Try to restart/reset your device. This won't delete your data stored on this device.

• Press and hold the Sleep/Wake button
• Press and hold on the Home button
• Keep holding both buttons until the display turns off and back on with Apple logo on it.

Alternatively, you may go to Settings - General - Reset - Reset All Settings

Also, take a look at these Apple Support articles:

Link your iPhone number and Apple ID to use iMessage and FaceTime - Apple Support

If you get an error when trying to activate iMessage or FaceTime - Apple Support