I was surprised that I hadn't done an Invoice Approval Flow in LSF9 until now and so didn't know about a potential problem. The WorkUnit created for the Invoice Approval wouldn't update beyond "Ready to Progess" until I added the AP26.1 & J-AP26.1 Form & Field Definitions.
This problem existed in 8.03 but the AP30.2 & J-AP30.2 definitions resolved that issue. Apparently in ProcessFlow 9 you have to also add the AP26 definitions and set them up exactly like the AP30.2 definitions.
Once this was done the next invoice I released was processed as expected in ProcessFlow. The ones that hadn't updated I went ahead and Released on the WorkUnit form and they processed.
