If e.g. the access modifiers of a guarded (FormEd-using) variable are changed (attempted) using an element node in the Explorer, the resulting error message just says "Exception in setter method" wh
ich is not at all helpful. In this case it looks like the actual exception is an InvocationTargetException wrapping a SourceException which may ultimately be wrapping a BadLocationException and so on.
 Somewhere the user should actually see what the problem is--the final dialog does not display any info about the exception at all.

This is only partially the problem of the element nodes--really there should be some sort of better convention for when to display exceptions from any modified property. Ian suggested at one time that
 there be a marker for exceptions with a reasonable display name, perhaps where the regular and localized detail messages differ, perhaps something else--in this case we should make sure this kind of
thing will properly propagate what is originally the Editor`s message about the guard blocks.