Enter a valid period

What causes this issue?

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

System Response

INCLUDE ICL_MESSAGE_DISPLAY OBJECT DOKU ID TX

How to fix this error?

Procedure for System Administrators

INCLUDE ICL_MESSAGE_CHANGE OBJECT DOKU ID TX
INCLUDE ICL_MESSAGE_CUST OBJECT DOKU ID TX

Error message extract from SAP system. Copyright SAP SE.