Vaadin 10+ Intro Exercise

I’ve downloaded Exercise for Intro and imported it into IntelliJ IDEA. But when I try to run:jetty I’m getting this error:

Failed to execute goal com.vaadin:vaadin-maven-plugin:14.0.0.rc1:prepare-frontend (default) on project exercises-intro: Execution default of goal com.vaadin:vaadin-maven-plugin:14.0.0.rc1:prepare-frontend failed: A required class was missing while executing com.vaadin:vaadin-maven-plugin:14.0.0.rc1:prepare-frontend: org/apache/commons/io/FileUtils

How do I fix this?