We propose an abductive model based on Constraint Handling Rule Grammars (CHRGs) for detecting and correcting errors in problem domains that can be desribed in terms of strings of words accepted by a logic grammar. We provide a proof of concept for the specific problem of detecting and repairing natural language errors, in particular; those concerning feature agreement. Our methodology relies on grammar and string transformation in accordance with a user-defined dictionary of possible pairs. This transformation also serves as top-down guidance for our essentially bottom-up parser. With respect to previous approaches to error detection and repair; including those that also use constraints and/or abduction, our methodology is surprisingly simple while far-reaching and efficient.