R12.1.3 Payables: APP-SQLAP-10264 error is thrown while new operating unit is setup In Financials During Setup Of New Operating Unit [2096022.1]

Article "R12 AP: Error APP-SQLAP-10264 In Financials Options During Setup Of New Operating Unit" on My Oracle Support via document ID 2096022.1 is a good one to read about why data validation is important and how automatic numbering can trip the system up.