Article characteristic &3 is not a planning level for planning step &1

What causes this issue?

You have selected the enhancement "Article Planning" for planning
layout &V2& (planning step &V1&). Before article planning can be run,
the characteristic with the meaning "Article" (in this case &V3&) must
be assigned to the appropriate planning step as a planning level. This
is not currently the case.

System Response

The planning scenario cannot activated before of this data
inconsistency.

How to fix this error?

Add planning level &V3& to planning step &V1& or do not select the
enhancement "Article Planning" for planning layout &V2&.
When you have done this, check the planning scenario again.

Procedure for System Administrators

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.