VBScript Issue in Grasshopper

Is VBScript fully implemented in Grasshopper for MAC Rhino 5.4 5E344w?
I have many problem to execute code that works fine on window such as a simple code like this:

Dim k As Integer = 0
K = 12

Error report: Ambiguous matching in method resolution (line: 0)

Atteched the image of the issue

can you try

Dim k as Integer = 0
k = 12
Print (k.ToString())

It works!

Thank you!