I have added the CM11A to the interface page and added lights to the light page but it is not obvious to me where you add the house code/address of the X10 modules i.e. A1, A2 etc
Open an internet browser. Type your LMCE Core IP in the address field.
Login with your LMCE user and password ( that you've created in the video wizard).
Go to Wizard -> Devices -> Lightning. Here you'll see all your lights. Be sure that every light it's "Controlled by:" CM11A.
Here you can set the
house code/address of the X10 modules i.e. A1, A2 etc
for every lightning device, the Room where it's situated, the type. Depending of What type(Floorplan Object) you choose the picture that appear in the Lightning Floorplan will be changed.