No outline agreements can be assigned to requisition (&/&)

What causes this issue?

You have attempted to list <GL:outline_agreement>outline agreements</>
that represent possible <GL:source_of_supply>sources</> for the
<GL:purchase_requisition>purchase requisition</>.
However the system was not able to find any outline agreements for
purchase requisitions of this <GL:document_type>document type</> or
this <GL:item_category>item category</>.

Error message extract from SAP system. Copyright SAP SE.