Problem in my project

The error…

Description    Resource    Path    Location    Type
Failed to resolve artifact vaadin-client-compiler (com.vaadin:vaadin-maven-plugin:7.6.6:compile:default:prepare-package)    pom.xml    /Vaadin01    line 125    Maven Build Problem

is occurring in my first project with Eclipse Vaadin Luna,
java 8.01.40, generated with maven.
How to solve this?
Thanks

I would first check that repository settings are right in pom.xml and after that if there is some proxy in your company network that prevents maven to access the repository.