Dates conflict with the dates of the subordinate WBS elements.

What causes this issue?

When you use top-down planning, the superior WBS elements determine the
time frame for each subordinate WBS element. However, the current start
and finish dates of the subordinate WBS elements fall outside of the
new superior time frame.

System Response

INCLUDE NA_ALLG_NOVERARBEITUNG OBJECT DOKU ID TX

How to fix this error?

INCLUDE 'NA_ALLG_MOEGLICH' OBJECT DOKU ID TX
Correct the dates in the subordinate WBS elements
Shift the WBS elements around within the project hierarchy (WBS).

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

Error message extract from SAP system. Copyright SAP SE.