After migrated my application from 7.7 to 8.0, I included all vaadin-compatibility, it works fine.
Tree was finally come out on Vaadin 8, so I migrated everything to 8 and removed vaadin-compatibility.
It compiled and run without problem within eclipse
But once I try to connect to the UI through web browser, I got following error:
Failed to load the widgetset:
Check out your UI class and look for this annotation:
@Widgetset("com.vaadin.v7.Vaadin7WidgetSet")
It’s used by the compatibility packages for the migration and if it’s still there it doesn’t need to be anymore.
If you have a custom widgetset you may also want to check your Widgetset.gwt.xml for this line: