SAP Message 5F491 - Employee identity unknown between period &1 and &2.

Diagnosis
The employee identity has not been entered into the system for periodV1 to v2.

System Response
The system displays an error message and is unable to check consistencybetween the social security number and employee gender.

Procedure
Enter employee identity for the period concerned (infotype 0002) beforeentering the employee's social insurance details