Depending on how your inverter is wired, have you checked the built-in 20amp circuit breaker in the Xantrex itself?
The E05 can mean overload or a short circuit. If something is shorting, it might have tripped the built-in circuit breaker on the side of the Inverter if...
1) You are using the built-in GFCI outlet for power
or
2) Your GFCI receptacle was pulled out of the Inverter and those wires were used to prove the AC output (that's the way Thor did it on my rig).
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