Connections using different emulators detected.
Violation of rule No.9
What does it mean? It means that when you switched off your DM800 box, you did not disable emulator running in the receiver. In your case, you had to stay on any FTA channel and disable it through the emulator menu.
When you connected your DM920Ultra, other emulator was enabled. So, server considered it connection using different emulators and gave you a warning.