Lesae API Error - Creating the lease record

we have create a lease by using Pn_Lease_Pub.Create_Lease API. We have passed Lease Details, Locations and Payments deatils to API.

1) The API return status is ERROR but the the still lease created without payment term.

       Error Message: Invalid payment Start Date: 15-DEC-19 and End Date: 14-DEC-19. The payment End Date should not be less than Start Date  

2) The API return status is ERROR but the lease created successfully and the error message are

     ->Invalid Discount Rate Index ID: &INDEX_ID or Discount Rate Index Name:&INDEX_NAME. Enter an index ID or name defined for the operating unit for which the lease is being          created or updated. You must also ensure that the effective start date of the Discount Rate Index is equal to or earlier than the lease commencement date.          (RATE_INDEX_ID=10035)      (RATE_INDEX_NAME=)