Upgrade problem from 7 .7 to 8.0 / com.vaadin.DefaultWidgetSet.nocache.js

Changed in pom.xml  version  of "vaadin-spring-boot-starter" to  2.0.0 and project upgraded to  Vaadin 8.0

Opens white page with message "Failed to load the widgetset: ./VAADIN/widgetsets/com.vaadin.DefaultWidgetSet/com.vaadin.DefaultWidgetSet.nocache.js?1487928644656"

In console message:
Requested resource [/VAADIN/widgetsets/com.vaadin.DefaultWidgetSet/com.vaadin.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.
 

Sorry, my problem, true configuration:
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.1.RELEASE</version>
        <relativePath/>
    </parent>

Without version:
<dependency>
            <artifactId>vaadin-spring-boot-starter</artifactId>
            <groupId>com.vaadin</groupId>
</dependency>

and vaadin 8.0.0 on borad!