I'm just a random dude who bought the software and has been playing with it a bit today.
I just made a simple project with a module, a variable called "date", an action with the c# code from the other thread, a "show variable" action and passed the result into the variable and the date and time showed fine. Make sure you filled out each of the fields and included the code exactly as provided. I'm putting the code here to make copying and pasting easy:
public class TestClass
public static string TestMethod()
Don't forget to fill in the namespace, class and method name fields, and save the result to the variable you want it stored in. I hope this helps :-)