I faced the same issue since last Windows Update on March 19, 2019. Creo View is blocked from launching in Internet Explorer. I tried a lot and found out that it works when you run Internet Explorer as Administrator.
To lauch Creo View successful, you need to enable Protected Mode in Internet Explorer for Local Intranet and Trusted Sites. Go to Tools > Internet Options > Security. Select "Local Intranet" and "Trusted Sites" Check the box "Enable Protected Mode" Restart Internet Explorer
PTC spent 8 months trying to resolve this issue and never did!!
We finally did some backdoor testing with a standalone install of Windchill11.0 and every CPS up to 06. They all launched CreoView, just not our production system. We then did a rehost of the production system (11.0 m030 CPS06) to the second set of servers and everything is working again. No explanation why it would not launch from the original servers. No changes to IE, no changes to URI calls, no system ports opened, just a rehost to aa new set of servers.