Saving of leave entitlement in IT 2006 failed

What causes this issue?

Saving of the new leave entitlement was terminated with errors.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Create the record manually for the personnel number. It is possible that
incorrect Customizing prevents the system from saving the record. After
correcting the Customizing settings, the missing record can
alternatively be created by running the payroll again.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.