What does

Run-time error '35603':

Invalid key

mean?

I get it when trying to execute a custom command - "dig" - which involves comparing a couple of variables. Seems pretty straightforward but clearly there's something suspect.

A post of the custom command would be good.

Have you checked that you don't have } else { ... or that you aren't using an invalid compare-thingy?

Looks like an internal Quest error - if you could please send me a copy of your ASL file I'll take a look into it.