Calling a Sub in VBA

Try -

Call CatSubProduktAreakum(Stattyp, Daty + UBound(SubCategories) + 2)

As for the reason, this from MSDN via this question - What does the Call keyword do in VB6?

You are not required to use the Call keyword when calling a procedure. However, if you use the Call keyword to call a procedure that requires arguments, argumentlist must be enclosed in parentheses. If you omit the Call keyword, you also must omit the parentheses around argumentlist. If you use either Call syntax to call any intrinsic or user-defined function, the function's return value is discarded.

For anyone still coming to this post, the other option is to simply omit the parentheses:

Sub SomeOtherSub(Stattyp As String)    'Daty and the other variables are defined here    CatSubProduktAreakum Stattyp, Daty + UBound(SubCategories) + 2End Sub

The Call keywords is only really in VBA for backwards compatibilty and isn't actually required.

If however, you decide to use the Call keyword, then you have to change your syntax to suit.

'// With CallCall Foo(Bar)'// Without CallFoo Bar

Both will do exactly the same thing.

That being said, there may be instances to watch out for where using parentheses unnecessarily will cause things to be evaluated where you didn't intend them to be (as parentheses do this in VBA) so with that in mind the better option is probably to omit the Call keyword and the parentheses