We upgraded a test instance of Oracle Financials (AP, GL, HR, FA) from 11.5.10.2 to R12.1.3. During testing, I encountered an issue when modifying a value of an employee type supplier specifically on the Invoice Management page (Payments tab), Supplier Site Region. I changed the value of the Pay Group but when I tried to save it, an error message stated: "Error: Supplier record cannot be updated. Either the Employee ID/Info is incorrect or the employee associated with this supplier is terminated."
I created an SR with Oracle but after 3 months of further testing and investigation, they concluded that it was due to incorrect setup and the solution was to create another org. No workaround can be provided. Let me explain the scenario: