Enter dates in the project definition first

What causes this issue?

You have not entered any start or finish dates in the project
definition. Therefore you do not have a time frame to work with for
planning dates of the individual WBS elements.
You can plan at the individual WBS element level without having had
entered start and finish dates in the project definition,
However, you should make sure you are not outside of the time frame
that project management has set.

System Response

INCLUDE 'NA_ALLG_VERARBEITUNG' OBJECT DOKU ID TX

How to fix this error?

INCLUDE 'NA_ALLG_MOEGLICH' OBJECT DOKU ID TX
Enter the start and finish dates in the project definition.
<ZH>or</>
Change the start and finish dates from time scheduling. Select the menu
options <LS>Goto -> Master data -> Project definition</> .

Error message extract from SAP system. Copyright SAP SE.