Hello. I was making a flight from Boston to Frankfurt in the PMDG 747-8 and FPS were excellent. around 30-40 and no issues. however around 3hrs into the flight just off the coast of newfoundland it just crashed with no error. looking at the Event viewer I found this: 

Application: Prepar3D.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: exception code c0000005, exception address 00007FFA28D7FB94
 

I am quite confused at what could cause this, but it was listed in the 1026 errors, and the details column gave me this: 

Application: Prepar3D.exe Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: exception code c0000005, exception address 00007FFA28D7FB94

 

 

From what I can tell this is a memory leak, which P3Dv5 is a bit infamous for at the moment. Is there any way I can resolve this? the last crash I had was a terrain.dll issue just over a week ago, so I'm going through some teething pains with the sim it seems. any help is appreciated. thanks.

That exception code is for a memory access violation. So the process stepped on some memory that it shouldn't have. This doesn't happen in managed code (.NET) except in very particular cases, but Prepar3d.exe is not a .NET executable itself, it just uses some libraries that are written in managed code. The main program is written in C++ which doesn't have the memory protection so it's much easier to run into this problem (for example if you use a stored pointer to memory which has been de-allocated). As to the why - I'm afraid it could be just about anything. If it's not happening reproducibly, the chances are it's down to some precise combination of inputs at that specific time that results in unexpected behaviour. 

The reason why exceptions logged when P3D crashes are almost always listed as .NET exceptions is because the .NET code running inside Prepar3d suddenly becomes unable to function due to the sim itself having crashed, and since this is an unexpected situation it isn't handled in the calling code and an unhandled exception is thrown by the .NET runtime which Windows picks up and logs. 

You'll usually find the P3D exception logs often in pairs - one is the 'normal' event logged by Windows when the C++ code crashes, and one logged by the .NET wrapper code when it dies. This contains the details of the faulting module (ie terrain.dll) which doesn't have to be a .NET module at all.

In terms of solving this? If you can't reproduce it reliably, there's basically nothing to do but hope it doesn't happen again. If it happens again, try to find the common factors to see if you can reproduce it. Otherwise remove all add-ons and run the base sim in the same scenario and see if it crashes there. If not, add things back in until something breaks.