I tried a fresh install of the below in this order:
KIAD
GSX
Standalone add on manager
I then performed a restart, I ran FSX, it lasted maybe just over one minute then crashed. Not sure if the below helps:
Faulting application name: fsx.exe, version: 10.0.61637.0, time stamp: 0x46fadb14
Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000005
Fault offset: 0xffb80027
Faulting process id: 0x1b80
Faulting application start time: 0x01d185cebfd861de
Faulting application path: C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\fsx.exe
Faulting module path: unknown
Report Id: 393a4a20-f1c2-11e5-8656-f079595c5b7e