Questions first, then possible issues.
Is this a new problem?
Have any other outlets been changed lately (before this issue)?
Is the coach "new" to you?
Has there been any wiring done recently?
New shore power cord?
By "works on inverter", do you mean when running the generator? Generator puts out 110 volts, just like shore power. I gather from the post that the breaker in the distribution box is tripping.
More information would help!
Sound like a gound/wiring issue. GFI = "ground fault interrupt". I.E. a problem with the ground/wires and the circuit is "interrupted" (shut down) to prevent shock.
The outlet (GFI) you replaced may not be the only outlet on the circuit. A GFI breaker can be used for a series of outlets. Check other outlets in the coach and see if they have lost power, too.
A bad CFI oulet in the wall will cause the circuit to trip. When replacing it, you have to be sure and wire it correctly.
Wires reversed in a newly replaced shore power cord or generator work could cause this, too.
Mike and Carla
1998 42' Overland Larado Diesel Pusher
On the road - here and there - Full Timing