retrieving a dynamic value throws an error

I have another last issue to solve:

if I write something like this:

mainMenu["b" + n].title.htmlText = parsedXML.SECTIONS.SECTION[n - 1].BUTTON.toUpperCase();

to  retrieve an object or an XML value DYNAMICALLY, Intellij marks it as an  error, i mean "title" and "BUTTON" are marked as unresolved variable  names. How can I do to disactivate this behaviour in the inspector?I've tried everything but still happen.

In  FDT it is possible...

PS: see attached image