Make .flt and .cfg files more sandboxed

When I make a mistake in a xml file, that part of the script just don’t work.
If I make a mistake (typo) in a .cfg or .flt file the sim crashes and it is
hard to get back in. No feedback on a console is given. I have to do an
external -rebuild sometimes. Is it possible to make the loading of those files
a bit less error prone? More sandboxed or something?