Vaadin 14 with Spring Boot


I am working with a project with Spring Boot and Vaadin and I am building it with Gradle.

When using Vaadin 13 everything is working, but when I try to run the program with Vaadin 14 I have the following error:

Caused by: javax.servlet.ServletException: com.vaadin.flow.server.ExecutionFailedException:

Do you know which is the cause of this? Or how could I solve it?

I have the following configuration for Vaadin in my file:

repositories {
maven { url ‘’}
maven { url ‘’}

dependencies {
implementation ‘com.vaadin:vaadin-bom:14.1.16’
implementation ‘com.vaadin:vaadin-spring-boot-starter’

dependencyManagement {
imports {
mavenBom “com.vaadin:vaadin-bom:14.1.16”

Thanks :slight_smile:

Hi! With Vaadin 14 in the compatibility mode, the client-side stuff was downloaded by Gradle (the -webjar.jars), and so no further compilation steps were necessary. However, with the new NPM mode the client-side is compiled/packaged with webpack, and so a specialized plugin is necessary.

There is an alpha release of the Vaadin Gradle Plugin - please feel free to give it a go and let us know whether it works for you :slight_smile: Please find the example project here: and the plugin itself here: