UE5.2 editor crash when startup map has spline attached niagara systems

Development Asset Creation FX
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1

i have a map with niagara systems that have 1 or multiple audio spectrums and may also have splines for alignment. the map loads fine in editor but when i set it as editor startup map it crashes in niagara.dll.

it “seems” to work if the systems and map were saved prior to 5.1. not 100% sure about that but the systems were changed and saved in 5.2 as well as the level.

does anyone have more info on this or a way to fix?

will try to gather some more debugging info

2

apparently the crash occurs somewhere here

void FNiagaraGpuComputeDispatch::PreStageInterface(FRDGBuilder& GraphBuilder, const FNiagaraGPUSystemTick& Tick, const FNiagaraComputeInstanceData& InstanceData, const FNiagaraSimStageData& SimStageData, TSet<FNiagaraDataInterfaceProxy*>& ProxiesToFinalize) const
{
	const int32 NumDataInterfaces = InstanceData.DataInterfaceProxies.Num();
	if (NumDataInterfaces == 0)
	{
		return;
	}

	const FNiagaraShaderRef& ComputeShader = InstanceData.Context->GPUScript_RT->GetShader(0);
	TConstArrayView<FNiagaraDataInterfaceParamRef> DIParameters = ComputeShader->GetDIParameters();

	FNDIGpuComputePreStageContext Context(GraphBuilder, *this, Tick, InstanceData, SimStageData);
	for (int32 iDataInterface = 0; iDataInterface < NumDataInterfaces; ++iDataInterface)
	{
		const FNiagaraDataInterfaceParamRef& DIParam = DIParameters[iDataInterface];
		if (DIParam.ShaderParametersOffset != INDEX_NONE)
		{
			FNiagaraDataInterfaceProxy* DataInterfaceProxy = InstanceData.DataInterfaceProxies[iDataInterface];
			Context.SetDataInterfaceProxy(DataInterfaceProxy);
			DataInterfaceProxy->PreStage(Context);  /// <<< CRASH here or line before
			if (DataInterfaceProxy->RequiresPreStageFinalize())
			{
				ProxiesToFinalize.Add(DataInterfaceProxy);
			}
		}
	}
}

and it seems to be related to the spline data interface. the map contains a few blueprint instances that have a spline, which has the niagara system attached. i removed those and the crash did not happen.

trying to pinpoint the exact issue

3

so i guess i found the issue.

if i have a blueprint that has a spline component, which has the niagara component attached and i have an instance of this blueprint in the level it crashes. (i don’t know if this is also influenced by the complexity or other used data interfaces in the niagara system.)

to solve the issue i did the following

create a blueprint that has a spline attached but no niagara system. then place this BP in the world and attach the niagara system as actor. now the map loads fine on startup of the editor