While Installing a Hotfix into our application through Hotfix Manager wizard we were getting displayed with error stating "Could not retrieve Catalog.zip from the DL file. The DL file may be invalid". Regarding this I found below link https://pdn.pega.com/support-articles/error-validating-dl-during-hotfix-installation ,"SA-30862". They have specified to install updated Catalog from "PRPC-Update-manager". So here my question is will this updated catalog affects existing HFixes in our application and how the Catalog.zip provided along with DL w.r.t HFIX differs with Updated Catalog.zip in Update Manager.