I really don't know what went wrong again with my P3D installation, I've had this failure many times already but it has been okay for the last week or so.
Name der fehlerhaften Anwendung: Prepar3D.exe, Version: 3.1.2.15831, Zeitstempel: 0x5672b60a
Name des fehlerhaften Moduls: ntdll.dll, Version: 10.0.10586.20, Zeitstempel: 0x5654262a
Ausnahmecode: 0xc0000374
Fehleroffset: 0x000dc089
ID des fehlerhaften Prozesses: 0x31a0
Startzeit der fehlerhaften Anwendung: 0x01d144e50cb1d880
Pfad der fehlerhaften Anwendung: D:\P3D V3\Prepar3D.exe
Pfad des fehlerhaften Moduls: C:\WINDOWS\SYSTEM32\ntdll.dll
This ntdll.dll has crashed my P3D many times as I said above, I now noticed it happens as soon as I start VPilot a software to connect to VATSIM, but it doesnt crash instantly, it crashes like 10 seconds after I connect to Vatsim.
EDIT: Alright I've solved this one alone and pretty fast. Seems like it was the same addon as last time causing this problem: The Majestic Dash 8 Q400. Uninstalled it and now P3D works great again.