Debugging NickelMenu is an exercise in frustration.
It'd be a lot less so if an error didn't zap all my custom menus, especially the one containing force usb...
Instead of ignoring all configuration, when it gets an error, could you have it add the config error to the menu as it does now and then do one of the following:
* stop reading config entries, but accept what it has read so far
* abort reading the current file (or ignore everything in the current file) but continue to the next file as if there was no error
* skip the flawed entry (and any following chained entries), but continue with the rest of the file
Ideallly, if there are multiple flaws, it might end up with multiple config errors in the menu.