Access Violation - Material Collection Parameter

We’re in the process of soak-testing our game, and have discovered a few engine-related crashes that come up occasionally either every few hours or minutes. I’m suggesting these for instability since our game does nothing but the same loop constantly. Sorry for the lack of clarity in the report, unfortunately this is the only information I’m being given, and annoyingly Visual Studio isn’t picking up the source code files and telling me exactly where it’s crashing.

I have attached the Callstack and the Log, and the log gives me two Access Violations and some more details. Perhaps this will help identify an issue here. We’re debugging in DebugGame, since it’s the Game we want to test now.

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Hi TheJamsh -

Hmm… Can you tell me how you are using the MPC(s) in your project? In particular how are the MPCs called in Functions either in BPs or in C++?

Thank You

Eric Ketchum

Some other items I noticed in the Log Files which warrant investigation is the -LocalNetworkVersion Number, the ActorChannelFailure. It almost looks like the player controller is not being initialized correctly because it is searching over a network for the information and cannot find it? Which if you are using the MPC on a Player Character model could cause an error like we are seeing the packaged callstack, particularly if the MPC is used in Constructor of the Player Character.

  • Eric Ketchum

Hi Eric,

The MPC is being used to set a Global ‘Light Vector’ which is used in an asset that is already placed in the world on level load (a gigantic Earth asset). It’s also used to track an objects rotation (from 0 > 1), so that we can pan textures based on it’s rotation (such as a Long-Lat view etc).

You could be right though, I’m not entirely sure that the error is in anyway related to the MPC, it might have been triggered from elsewhere. Our PlayerControllers are already in the world at this point and no more would have been spawned or any removed.

Unfortunately when I run in Debug Game, it doesn’t seem to give me any line numbers in UE4 source code (even though it’s part of the Solution file), or take me anywhere in the source code. I’ll keep trying to reproduce the issue and hopefully it’ll load debug symbols properly next time!