Missing Plugin GWT error in Eclipse

I'm trying to run an existing GWT project in Eclipse as a Web Application. This runs on other people's PCs, and I used a setup document common to us all to install Eclipse and GWT. I consistently got the error:

Google Error Not Found The requested URL /missing-plugin/ was not found on this server.

So far, I have verified that the GWT SDK is installed, and that the Google Plugin for Eclipse 3.5 is installed. I uninstalled just the Google Plugin, and then everyt开发者_运维技巧hing Google, and reinstalled, with no luck. at this point, after poking around a lot, all the Google stuff is installed, but the "Run as Web Application" option is completely gone. I've googled this, but no luck so far.

Any ideas?

As of GWT 2 (or there about), a new browser plugin is required for developer mode. You can get it here: http://gwt.google.com/samples/MissingPlugin/MissingPlugin.html