Original material & is a value-only material

What causes this issue?

Original materials <ZH>cannot</> belong to the following material
categories:
Generic material
Merchandise category material
Hierarchy material
Group material
Merchandise category reference material
Standard material

System Response

If the original material belongs to one of the above material
categories, the system does not create any follow-up/replacement
material relationships.

How to fix this error?

INCLUDE ISR_PR_FEN

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.