I visited a site that requires Java Runtime Environment to run.
I always faced the above mentioned thread title error.
i tried un-installing and re-installed, but still the same. Until I go to my com and adjusted one parameter on the internet setting, tick on the 'check for server certificate revocation' and i tried ok!
But the next day i tried to access the same site (which require the JRE), I encountered the same error again.
This application error state ' net.Slingshot.Viewer.Viewer.Class'
That message is printed by the Java Runtime Environment. Ergo it is installed correctly, ergo uninstalling and reinstalling it was a waste of time. The problem is due to some mis-installation or misconfiguration of the application that contains the named class. You will have to take that up with its authors.