I am trying the trial version of GXT 3.0, I am following the online tutorial but when I run the application I get the error:

Unable to find 'com/sencha/gxt/ui/GXT.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source?

in the Test1.gwt.xml file I have added:<inheritsname='com.sencha.gxt.ui.GXT'/>

I have added gxt-3.0.1.jar to my project class path using "Configure Build Path" and the jar appears in the list of jars in "Project Explorer". As I was getting this error I also tried to check "gxt" in the "Order and Export" tab in the "Java Build Path" dialog.

A standard GWT project builds and runs fine.

Nothing worked, any advice?