Accessed None trying to read property CallFunc_SpawnSystemAtLocation_ReturnValue

Development Programming & Scripting C++
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1

Hi everyone,
I am trying to implement a blueprint event to emit a niagara system, from C++. However, I get the following error: Accessed None trying to read property CallFunc_SpawnSystemAtLocation_ReturnValue

The blueprint looks like this:
image
(ignore the simulating part)

And the call like this:

ShowHitscanFireEffectTP(
				EmitterStartPoint,
				EmitterEndPoint,
				NiagaraSystem
);

The values all are fine, and valid, and I have a blueprint that matches the blueprint shown above, but which works fine. The only difference is that the working blueprint is run on clientside, and this malfunctioning one is run on server side.

I can’t find any answers to this anywhere, please help me.

Thank you.

2

Are you passing in the niagara system on the server side when calling this function there?.

You can do a isvalid test right after the function and if its not needed on server then skip directly to physics function.

If you do need it on the server then step through the code on the server where it is called and check why it is null.

3

Thanks for the reply.

I have since realised it would be better to simply replicate the effect directly to all other clients - I think the problem is that dedicated servers cannot display Niagara systems but not sure, although this would make sense as they do not process graphics, and a niagara system is graphics.

The replication system works fine, no more problems.