I have a process that is creating Manual Customer Invoices, via the ManualCustomerInvoiceAssistant.   As long as the client has the Auto-Post invoices turned off the process works.   If it is turned on I get the error message

 "ORA-20110: ManualCustomerInvoiceAssistantHandling.USERGRPGLOSED: Period is Closed for the User!"

If I include the Accounting Period and Year in the Create Virtual Invoice I get the error 

ORA-20121: ManCustInvoice.INSERT: Field FACC_YEAR_INVOICE_DATE] in Man Cust Invoice may not be specified for new objects."

Is it possible to use the ManualCustomerInvoiceAssistant APIS and have the Auto-post invoices enabled?

Walter