Don't leave the storyboard parameters blank, make an empty filler for it. (Intro.def and Intro.sff with practically nothing in them.)
Oho, didn't know about that one. So, you're saying that this:
[Arcade]crashes Linux Mugen?
But, what if you simply leave out those parameters entirely? That is, what if the DEF file ends immediately after "[Arcade]", or if the [Arcade] section simply doesn't exist?
Anyway, thanks for posting that.
Still quite busy.
(Yes, I intend to deal with that stuff eventually, but kinda can't just yet, sorry. :/ )