&4 &1 contains non-numeric characters

What causes this issue?

&V4& &V1& for the recycling partner &V2& does not contain numeric
characters. A mathematical comparison is however necessary for
settlement purposes.

System Response

&V4& is set globally to &V3&.

How to fix this error?

Change the &V4& in the recycling partner and in the article master data
maintenance.

Error message extract from SAP system. Copyright SAP SE.