How to iinclude Vaadin charts into my Project.

Hi,

I trie to add Vaadin chars into my Java project, but it allways ends in a classnotfoundexception.

I use Vaadin 7.7.10
Eclipse Mars

I followed the instructions here:
https://examples.javacodegeeks.com/enterprise-java/vaadin/vaadin-charts-example/
It works up to the point when I try to enter a screen using charts where i get the Noclassfound exception

My problems are if I change the version number in the IVY.xml I get an error:
Some projects fail to be resolved
Impossible to resolve dependencies of com.example#v7proj;working@LAPTOPAG
unresolved dependency: com.vaadin.addon#vaadin-charts;3.2.1: not found

I#m not sure what I should do now. I’m also not sure where to look.

Thanks in advance.