Vaadin 10: ReferenceError: Polymer is not defined

Flow
1

I just created a new project with Spring and Vaadin 10 with the following dependencies:

<properties>
    <vaadin.version>10.0.1</vaadin.version>
</properties>

<dependencies>
        <dependency>
        <groupId>com.vaadin</groupId>
        <artifactId>vaadin-spring-boot-starter</artifactId>
    </dependency>
</dependencies>

   <dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin</artifactId>
            <version>${vaadin.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

I then added a very simple view:

@Route("")
@PageTitle("Hello World")
public class LoginView extends VerticalLayout {

    public LoginView() {
        add(new Button("Button?"), new Label("Label?"));
    }
}

Now I’m facing the problem, that the Lumo (default) theme is not applied to my view and that the VerticalLayout doesn’t align my elements like it should do. I then checked the console and it showed the attached errors.
17147104.png

2

UPDATE: I just solved the issue by clearing my maven cache