Users can't use Universal Plugin Manager to download / install add-ons

Summary

Users can't use Universal Plugin Manager to download / install add-ons.

Steps to reproduce

1. Navigate to Manage add-ons page - /plugins/servlet/upm/marketplace/
2. Try to install any add-on

Observed problem

Cause

 This issue is caused by a temporary domain name change for Marketplace add-ons. If your firewall rules only allow connections to marketplace.atlassian.com and marketplace-cdn.atlassian.com, you would be affected by this.

Workaround

There is a temporary workaround available to whitelist marketplace-cdn.prod.public.atl-paas.net in Firewall rules in addition to marketplace.atlassian.com and marketplace-cdn.atlassian.com. This is only temporary and can be removed after this issue is resolved.