XPRA not executed because system is a content system

What causes this issue?

In a Content system, external hierarchy characteristics are not
automatically stored in the hierarchy basis characteristic using the
XPRA. This is because the system cannot check to see whether the
InfoObjects are relevant for delivery. The person responsible for the
hierarchy DataSource must manually enter the relevant external
characteristics.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.