No C/I methods assigned to consolidation units

What causes this issue?

In dimension &V2& and version &V3&, no consolidation of investment
method is assigned to one or more of the consolidation units in the
consolidation groups
&V1&

System Response

Processing terminated

How to fix this error?

Assign a C/I method to each of the consolidation units in the
consolidation groups listed above.

Error message extract from SAP system. Copyright SAP SE.