I spent an hour staring at my gwt.xml file trying to figure out what I had done wrong after restructuring a project. Turned out it was in a sub-package of client instead of client itself. Right at the bottom of a long list of packages and sub-packages too. So in Eclipse’s tree view, it looked like it was in the right place. Finally I realized it was one level in too deep. Face-palm time. I would also study the Run Configurations. If you are using Eclipse and you regularly do a “Run As” then “Web Configuration”, this time do “Run As” and select “Run Configurations” at the bottom of the sub-menu. Go through it, tab by tab, but in particular study the “Arguments” tab and see if it needs to be updated. You can also get to the settings view the Project -> Properties -> Run/Debug Settings.