I have two copies of the same non-nbsrc NetBeans module open.  One is a checkout from an SVN server of its current
contents.  The other is a copy with modifications which I recovered after a disk crash.

In the old copy exists
public abstract class JCProject { ... }

In the new copy exists
public class JCProject { ... }

When I invoke a constructor in the copy with modifications
new JCProject();

I get the hint Implement all Abstract Methods - the hint is getting its metadata from the wrong copy of the project.

This also affects debug info, and I've been having problems with exceptions thrown from lines that, when I search for
them, are javadoc comments.  Something about the way NB project class metadata is stored does not include tracking the
path of the project.