Vaadin bundle don’t export package VAADIN/widgetsets, the Export-Package field doesn’t contain this package. So, the exception appear when other bundle try access to resources in this package. This is log message:
[VAADIN/widgetsets/com.vaadin.terminal.gwt.DefaultWidgetSet/com.vaadin.terminal.gwt.DefaultWidgetSet.nocache.js]
not found from filesystem or through class loader. Add widgetset and/or theme JAR to your classpath or add files to WebContent/VAADIN folder.|#]
Also there are appear dialog with similar message and ui don’t load.
Is it a bug?