You cannot delete indiv. variants with pricing reference material

What causes this issue?

You want to deleted individual variants of the generic article. The
generic article is the pricing reference material for these variants.
Not all variants are to be deleted.

System Response

Variants which have a pricing reference material can only be deleted if
the pricing reference material is also deleted. If the pricing
reference material is a generic material, it can only be deleted if all
all the variants are deleted as well. If you only want to delete some
of the variants, then these must not have a pricing reference material.

How to fix this error?

Delete the pricing reference material in the material master for the
variant and then delete the variant.

Error message extract from SAP system. Copyright SAP SE.