&1 &2 contains only one material

What causes this issue?

&V1& &V2& contains only one material.

System Response

As &V1& &V2& contains only one material, it cannot be used for the
processes of material requirements planning, purchasing and sales.

How to fix this error?

Check your entries.

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.