Replace Structurally script does not work for Method calls

Hello I tried to change the paramter of an method call with a script in replace using the parameter defined in the search.

Search template:

$Instance$.$MethodCall$($Parameter$)

Replace template:

$Instance$.$MethodCall$($Parameter2$)

where the $Parameter2$ has a script that is: Parameter.name.toUpperCase()

This results in:

Structural Search script threw an exception: java.lang.NullPointerException: Cannot invoke method toUpperCase() on null object

When I do the same thing on a type declaration it works

$FieldType$ $Field$;
$FieldType$ $Field2$;

Field2 has script: Field.name.toUpperCase()

Why does it not work with method calls?