Mass Traffic Assertion Failed: Zone Graph Storage

[Staajabu]

Please help! I keep getting this error when I run new projects using City Sample Vehicles on UE 5.3.2 (Windows 10) and UE 5.4.4 (Windows 11) … on two different machines with different specs!

Neither version of Unreal has an option to turn off traffic multithreading by using the console command “ai.traffic.parallelize 0”.

We followed the instructions shown at the video link below but the program crashes and I do not know how to fix the issue after trying out a variety of solutions. Funny thing is it works just fine in the City Sample on both machines, but not in my projects.

UE5 MassAI Traffic in your project step by step guide #UE5

[FrostyJas]

Greetings @Staajabu

Welcome back to the Unreal Forum! I pulled an old post with a user having this issue, I believe. Take a peek here and see if their solution works for you as well. Let me know!

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Hello, Looking for assistance with this crash from trying to set up the mass traffic AI in my project. Any help much appreciated. works if you use the crowd AI to spawn a character that is assembled out of the car mesh and uses the character nav, but crashes when trying to use zonegraph with traffic AI spawn system. Assertion failed: ZoneGraphStorage [File:D:\build++UE5\Sync\LocalBuilds\CitySample\Windows\Plugins\Traffic\Source\MassTraffic\Private\MassTrafficLaneChangingProcessor.cpp] [Line: 6…

[Staajabu]

Hi @FrostyJas

Thank you for the follow up. Yes I saw that post prior to posting here. The MassCrowd AI works just fine but new MassTraffic AI projects do not work even for a new level, new file, and even different computer with a different Windows operating system. I also tried deleting my “saved” folder as recommended by others but that did not fix the problem either.

[Staajabu]

I finally found a solution for Unreal Engine 5.3.2 and 5.4.4 on github.
The additional step needed is to add “Assorted Fragments” in the “CarAgent” data asset as shown below:

The solution is explained in github at this link [GitHub - Myxcil/MassTraffic-Test: Mass Traffic plugin extracted from CitySample for UE 5.4. Trying to understand it](On Github at Myxcil/MassTraffic-Test)

The other issues I need to troubleshoot are as follows:

1. Why do vehicles spawn in paths tagged for pedestrians?
2. Why do some cars eventually stop?
3. Why do some cars have random wheel meshes missing?

[FrostyJas]

Oh!!! Right on! Thank you for sharing that and I’m happy you found the solution!