Installed base could not be determined for product &1

What causes this issue?

There is no unique assignment for product &V1& on &V2& at &V3&. One of
the following cases applies:
The product is not assigned to an installed base
The product is assigned to more than one installed base
The product is assigned to one installed base more than once

System Response

The system will not continue processing.

How to fix this error?

Use the where-used list to check the assignment of products to the
installed bases.

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.