&-& (foreign key definition is partial)

What causes this issue?

The foreign key was not fully defined in the ABAP/4 Dictionary
maintainance. Full maintenance means that exactly one field from
the table to be checked is assigned to each key field in the
check table. The fields that are assigned to one another must refer to
the same domain. The field assignment must always contain the check
field (the field with which the foreign key was defined), the position
of this field being irrelevant.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

The ABAP/4 Dictionary table can only be activated if the foreign key has
been defined fully.

How to fix this error?

When maintaining the foreign key, all key fields from the check table
must be assigned to fields from the table to be checked (foreign key
table).

Error message extract from SAP system. Copyright SAP SE.