When I tried to enable the VUM for vSphere 5.1 (another issue I'll address in a different thread but if anyone has information on that, by all means chime in here), I also noticed there were 2 other errors displayed in the Plug-in manager:
The following error occurred while downloading the script plugin from https://x.x.x.x:8443/cim-ui/scriptConfig.xml: The client could not send a complete request to the server. (The underlying connection was closed: An unexpected error occurred on a send.)
The following error occurred while downloading the script plugin from https://x.x.x.x:8443/health-ui/scriptConfig.xml: The client could not send a complete request to the server. (The underlying connection was closed: An unexpected error occurred on a send.)
I'm not even sure what this is nor how to correct this issue but this is a new install of vCenter on a Windows machine and I don't like to see errors. Is this a firewall issue? Something else? Where do I start?