 <p>I had the same problem and finally found the solution. Hope it works for you too. Follow these steps and then try to install the plugin again.</p> <p>Select Help > Install New Software... Select the Helios update site in the Work with dropdown. If it's not there, you can enter the URL directly: <a href="http://download.eclipse.org/releases/helios">http://download.eclipse.org/releases/helios</a> Install Helios > Web, XML, and Java EE Development > Eclipse Web Developer Tools.</p>