The VTScada help file indicates that the RadioButtons function should be called using the Dot notation:

\System.RadioButtons(.....);

When I attempted this implementation the radio buttons did not show up in my display. After verifying my variables I tried using the "\" notation:

\System\RadioButtons(......);

This worked.

(Full Disclosure: I'm using the VT11 era "CompletedTutorial" application as my 'Sandbox' on VT12)

Old application means old properties. The one you're tripping over is LocalScopeSyntax. The docs will guide you from there.