ISO is not created and requistion is in error correction form with below error message
ORA-20001: APP-FND-01728: An assignment does not exist for these parameters.
Cause: An attempt was made to find a sequence for this document flexfield. The profile option says Sequential Numbering is only partially used.
Action: None is necessary unless you expected this document flexfield to have a sequence defined. in Package OE_Header_Util Procedure Get_Order_Number