Environment

ZENworks 2020 Update 3 or higher 
ZENworks Patch Management

Situation

This article explains the steps to verify the manual download of any Patch Contents from ZENworks OCM Primary
It allows troubleshooting any issues where downloading of patch contents fails on the ZENworks agent due to 503 or 404 errors.  

ZENworks contents can be linked contents(Bundles, policies, system updates) or non-linked contents (antimalware or patch). The non-linked contents are hosted on the Primary Servers under the content-repo into the ondemand-content path. These non-linked contents are typically associated with Patch(content or catalog), Antimalware(metadata or contents)

Managed devices can request the linked or non-linked contents using the On-demand method. The content servers can download the requested on-demand content from its upstream source if missing locally. 

Any such content that is streamed on-demand from the managed devices, will eventually reach out for a download request to the OCM (OnDemand Content Master) Primaries
In case these contents are not available/cached locally in the content repository of the OCM Primary, it will be downloaded from an external source based on the OndemandContentProxy.json configuration file. 

For any additional information refer to the On-demand documentation at https://www.novell.com/documentation/zenworks-23.4/zen_ondemand_content/data/sect1template.html