Trouble with Ingemann's approach is he is de facto discussing if Socialism can work - not Communism.
This is of course a more relevant topic, but not what the OP wanted to discuss.
Again, the Eastern European dictatorships did not claim they had implemented Communism, just that they were Socialist societies. If you moderate them towards a mixed economy, that is even further from Communism.
I think it's meaningless to discuss a theoretical construction instead of what people mean when they're talking about Communism, the kind of institutions we saw in the east block.
Would what you mean with Communism function; of course not, neither would any other platonic ideal. So let's not discuss platonic ideals and deal with whether you could produce a functional real world example of the ideology.
It is not about what I call Communism, but what Communists themselves called communism. They did not claim their societies were communist. It was the Union of Socialist Soviet Republics, not the Union of Communist Soviet Republics.
It is not a given that a non-Leninist version of Communism closer to the ideals of Marx could not function (leave Platon out of this, he is not relevant). How close you could have gotten to the ideal is hard to access, but I think it is a given that you could have gotten much closer than the Leninist societies.
The Leninist models are not a good starting point for accessing whether it was possible to construct a functioning Communist society. Leninism was efficient in obtaining power, but it also ruined any real development towards Communism because it created enormous incentives for a bureaucratic elite to halt any development towards genuine communal ownership of the means of production by the people, workers influence and the demise (or even reduction) of the state.
Also, like I said, you move away from Communism towards Socialism if you take a mixed economy version of Yugoslavia as your starting point. A successful revolution in Germany in 1919 is a better starting point if you want a RL timeline.
Whether Socialism can work is more relevant than whether Communism can work, but it is a separate issue and not what the OP asked. If you want to debate that you should create a separate thread.