The ADF Lifecycle occasionally handles some exceptions and doesn't propagate them anywhere useful. This can be frustrating when you are encountering some strange behaviour but can't determine the cause.
When running the embedded OC4J container with JDeveloper you can enable debug level logging mode which will cause ADF to log all SQL statements, exceptions and other info to the Embedded OC4J containers log window in JDev.
to enable debug mode, right click on your ViewController project and select properties. Then select Profiles->Development->Runner nodes. In the java options field add the following:
-Djbo.debugoutput=console