Check if you didn't forget to copy the class file mentioned in the exception code to $JAVA_TOP.
You have a different solution? A short tip here would help you and many other users who saw this issue last week.
- oracle.apps.fnd.framework.OAException: Could not create Java class: (xx.oracle.apps.ap.invoice.request.webui.XxInvoiceRequestPGCOExt7) associated with region: (InvoiceRequestPGLayout). This is probably because the class name is wrong or not included in project. at oracle.apps.fnd.framework.webui.OAPageErrorHandler.prepareException(OAPageErrorHandler.java:1247)