Error while determining condition types

What causes this issue?

During the declaration of document &V3& reductions were calculted to
the amount of &V1(C)& EURO, which could not be assigned to any
condition type.

System Response

On document 70 a condition type &V2& with the amount of &V1(C)& is
output in order to correct the full settlement.

How to fix this error?

Please check, if a condition type &V2& has been assigned to all
articles settled by re.partner &V4& using the
<DS:DE.J_7LKOKEY>SplitKey</>.

Error message extract from SAP system. Copyright SAP SE.