Why do I get the error: Attempted to access index 1 from array?

Blueprint Runtime Error: Attempted to access index 1 from array CallFunc_ParseIntoArray_ReturnValue of length 1! from function: ‘ReceiveChatMessage’ from node: Spawn Emitter at Location in graph: ReceiveChatMessage in object: ChatWindowActor with description: Attempted to access index 1 from array CallFunc_ParseIntoArray_ReturnValue of length 1!

I’m receiving several strings from a server into unreal e.g
data[0] = “500,400,399”;
data[1] = “453,544,333”;
And I’m splitting it and using the splitted values as x,y,z coordinates.