Call to function aFunctionName has too few parameters
sRESULT = EvalToken('[Dddd]') // incorrect
sRESULT = EvalToken(n_TokenDate,'[Dddd]') // correct
This usually occurs, as above, when one of the parameters is "obvious" in your mind, but not for the compiler.
You can avoid using the wrong number of parameters (or in the wrong order), by using the Code Completion feature. Whenever you are about write a function call, press the F3 key, and select the function from the list which appears (you can even get help on each function while the list is up), by clicking on it.
The function name will then be pasted into the code editor, where your cursor was, showing plainly the number and type of arguments expected by the function.