Structure tool not available for Lua files

Hi,

I have the Lua plugin installed and it seems to basically be working (I can see validation error messages for example) but one thing that isn't working, that I believe used to at some point, is the structure tool window.  It's grayed out on the View menu  I'm not sure if this is a pluing problem or an IDEA problem.  Does anyone have any insight by chance?

Thanks,
Frank