SAP Message 3E068 - Invalid remittance begin date

Diagnosis
You entered an invalid remittance begin date. The remittance begin datemust be the 1st or 16th of the month.

System Response
The system cannot create the remittance certificate.

Procedure
Change the remittance begin date.
For example, in April 1999 the remittance begin date can be:
01.04.1999
16.04.1999