LaTeX problem with apacite

After spending 2 hours in searching an error in my publication draft, I would like to share my gained knowledge. The problem was, that using the apacite package caused an error, the second citation command would not have the correct number of parameters. It turned out, that the babel package was the problem, more exactly the order of usepackage commands. First the babel package, afterwards the apacite package – that was the solution.