Partner &1 cannot be used, as per contract &2

What causes this issue?

Partner &V1& cannot be used for transactions since it is not assigned
a valid role as from the "date on which contract was concluded" &V2&.
The role defines the partner as the counterparty.

System Response

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

How to fix this error?

Use a different partner with the valid role of "Counterparty" or
assign the role of "Counterparty" to partner &V1&, or extend the
validity of this role.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.