Hi, folks, I've been working on this by eliminating guages as JohnCi suggested and it seems to be caused by the Garmin GPS's. Another ac I have, The Poman's Meridian uses these same guages and runs fine. Anyone have any idea why this should be? Have to go now and do a honeydo, later I'll try the Meridian panel in the Extra..JamesJ

Back again..I tried the Meridian panel which has the exact same Garmin Gps's installed and it works fine in the Extra400. The Extrea400 panel when installed in the PoMan's Meridian causes the same problem..sim crashes to desktop with the Microsoft error message. I negated the two Garmin Gps's in the Extra Panel and placed some other guages in their place to give a Radio stack, etc. and everything is fine..JamesJ