I recently have problems with my Q400 in FSX-SE and I do not remember what I might have changed.
When I load the Q400 (after loading the C172) the systems start to initialize but there remain 3 failures:
PFD: ATT-fail, HDG-fail, IVSI-fail, "Aligning" forever
MFD: Oil temperature out of range (something like minus 2 billion degrees)
FMS: AHRS input fail
Btw, the CoPilot's Display is fine.
But, when I load an older saved flight, the Q400 works as expected.
Things I have tried:
Multiple Reinstallation of 1.016, 1.017RC2 and 1.018beta
In Control Panel, change to Multimedia Timer and disable FDE2FSX-sync
My next step would be to reinstall FSX, but it's a lot of work.
Any advice would be appreciated.