The vendor has published 2 unique mention(s) for this bug: 1. Delivery Controller™ fails to upgrade from Citrix Virtual Apps and Desktops 2402 CU1 to 2503. 2. Delivery Controller fails to upgrade from Citrix Virtual Apps and Desktops 2402 CU1 to 2503. Latest urls for this bug: 1. https://docs.citrix.com/us/en/citrix-virtual-apps-desktops/2503/whats-new/known-issues.html 2. https://docs.citrix.com/us/en/citrix-virtual-apps-desktops/2507-ltsr/whats-new/2507-ltsr-initial-release/fixed-issues.html