Could not download the Silverlight application or the Silverlight plug-in did not load. To re-configure the Web Part or to ...

Could not download the Silverlight application or the Silverlight plug-in did not load. 
To re-configure the Web Part or to provide a different location, open the tool pane and click Edit Web Part.  This message can also indicate that the server that Web Part is configured for is down or offline, or that the HostUri in the Operations Manager web console environments list for the Administrative web site is incorrect.  For solutions using slower network connections, you can configure the amount of time we will wait before displaying this message.  To configure the setting, open the Web Consoles list in Central Administration, and set the HostErrorTimeout to something greater than the default of 5 seconds.