I have this issue with the Longitude in that I cannot fire it up without external power.
try to select batteries, cannot press the buttons although the helping hand illuminates when I hover over them, select external power and everything comes on, start the APU and bring it online, try to select batteries again cannot turn then on.
Turn external power off and aircraft shuts down.
I believe the issue is the fact that I cannot select the batteries on .
I have tried uninstalling the aircraft and removed my community folder but, still the aircraft has become unusable.
Any suggestions appreciated