I would (1) investigate the scope of the issue; (2) inform my supervisor with an approach to remedy the issue; (3) gather all people/groups needed to resolve the issue and put together a plan of attack; (4) inform the client/attorney of the issue and our move-forward plan, providing a realistic completion time; (5) keep my supervisor and the attorney up to date on our progress; (6) after completed, do a post-mortem on what happened, why it happened, and how we can prevent it from happening in the future