I've been sent here from Prepar3d forum topic url: http://www.prepar3d.com/forum/viewtopic.php?f=6312&p=143613#p143613
In short: if saved PMDG flight is set as default, then Prepar3d v3.4 does not run properly - either you get black screen or app dissapears.
It is still visible in process explorer with about 2% CPU utilisation, 0% GPU, about 800MB vas, but you cannot bring the process into front as there is no windows available.
In that case, deleting 'situation' line in prepar3d.cfg and restarting p3d solves the problem.
Can you suggest how to solve or do further problem diagnostics?
Windows 7 ultimate 64bit
i7 4770k @4.6 watercooled
GTX 780TI with latest drivers
Prepar3d on a separate raid0 ssd array
Pilot's 2010 FTX mesh
Orbx Global, Vector, LC EU, LC NA, Norway, England, Wales, Scotland, Ireland, Norhern Ireland, ESSA
Aerosoft Oslo 2.0, Zurich 2.0
PMDG (installer downloaded today, all simconnects installed from p3d redist)
ASNext beta for p3d 3.4
Rex textures with soft clouds
FSUIPC latest, registered
Precipit FX, 737 immersion pack
EZDOK and F1 GTN750