When I try to install the Ruby RDT (v7) for Eclipse 3.1.1 by
downloading the file and upzipping it into the Eclipse directory, the
plugin installs in that I can see it listed as a plugin, but the
Preferences page for it produces an error:
Unable to create the selected Preference Page
Plug-in org.rubypeople.rdt.ui was unable to load class
I can see that this file is in a zip file, but Eclipse can’t see it.