IllegalStateException Displayed in the Log Window
By Didier Laurent on May 23, 2006
When you re-run or re-debug an application in JDeveloper without stopping the embedded OC4J,
you may get a java.lang.IllegalStateException displayed in the Log window:
This error can be ignored.
To avoid it, just stop the Embedded OC4J Server after you tested or debugged your application.
For more detail, read this article.