[BUG] Unable to run packaged game, containing a blueprint actor with 5 or more HierarchicalInstancedStaticMeshes

Can confirm, this is indeed a bug…just ran into this during a package test for the gamejam… GGWP… This is fine in editor… just not good in packaged.

One workaround is to use ISMC instead until they fix it… sucks that we have to use a workaround, but it worked for me. Hope it works for you.

i found that for me it cooks and does not crash if cooked for shipping,
but if you cook for development it will crash when trying to load any map contain any hism actors.

Hey,

Sorry for the delay and I’m glad you found a workaround.

I was able to reproduce this in 4.16, but I was unable to repro it in 4.17 Preview 1. So you should see this working properly once the full 4.17 is available.

-TJ

If a blueprint actor has more than or equal to 5 different HierarchicalInstancedStaticMesh placed in the construction script, and the game is packaged for Windows (64-bit) with at least one of these in the world, then the packaged game is unable to run, returning “Assertion failed: bIsGrass || WriteOncePrebuiltInstanceBuffer.NumInstances() == GetNumRenderInstances()
[File: \Build++UE4+Release-4.16+Compile\Sync\Engine\Source\Runtime\Engine\Private\HierarchicalInstancedStaticMesh.cpp][Line: 2527]”
(Using 4.16.2) once the built version of the game is run.

Steps to reproduce:

  • Create an actor blueprint
  • Create 5 different HierarchicalInstancedStaticMesh (I used “shape_Trim_90_Out”, “SM_Lamp_Ceiling”, “SM_TableRound”, “SM_WindowFrame” & “SM_Arrows” from the default content to test)
  • Make sure that all 5 meshes are placed (since according to my testing it is only when it is above 5 meshes the error occur)
  • Run a loop placing them (I just used flip-flops to test) in the construction script
  • Place the actor in the world
  • Package for Windows (64-bit)
  • Run the packaged game
  • Experience the error

I found also that is crashes with anything more than 1 hism mesh within a bp actor placed in a map that you trying to open

4.17 does work now to package, but if you toggle the HLOD actor’s visibility to hidden it won’t toggle back for some reason. It works fine run from the editor, it only breaks in the packaged version.

Excuse my ignorance, but what is ISMC?

Instanced Static Mesh Component