These are errors common to all VISA (most USB and ethernet devices) connected devices.
??? Error using ==> icinterface.fprintf at 147
VISA: The connection for the given session has been lost.
USB and Ethernet VISA connections will be closed if the device is disconnected or rebooted. smclose and smopen the device.
-500,"Power On"
The AWG was just turned on. Harmless, ignore.
"Sequence/Waveform loading error; E11203 - AWGC:RUN"
No waveform defined for one of the channels. Probably the AWG is not in sequence mode.