SAP ArchiveLink: Storage system & not known (Customizing)

What causes this issue?

A request was to be sent to a content server which is not known in SAP
ArchiveLink administration.

System Response

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

&WHAT_TO_DO& for system administration:
Check the function "Content repositories" in Customizing:
<DS:TRAN.OAC0>Execute function</>
&v1&
&v2&

Error message extract from SAP system. Copyright SAP SE.