This problem can also happen when you have two projects open, and one project references jars built by the other. If you go back to the project which owns the jars and attempt to rebuild, JBuilder can corrupt the jars due to the other project still having the jar files open.

The application runs just as well by reading the individual class files direct from disk, and that's what I do until I'm doing the final builds for customers. (I'll have the project create the jars, as you do, but I don't define them as required libraries, I let it use the class files.)
2002-Feb-13 2:51pm gyles19@visi.com