SAP ArchiveLink (SAP kernel error)

What causes this issue?

A request was to be sent to a content server.
The SAP kernel could not forward the request to the content server.

System Response

An error was reported by the SAP kernel.
The SAP kernel has probably not received a response to its request
because the content server connection is not active or cannot be
accessed (TIMEOUT).

How to fix this error?

Repeat the request. If the error still occurs when the request is
repeated, the error cannot be corrected in the application. Contact
your system administrator/content server administrator.

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

Error message extract from SAP system. Copyright SAP SE.