Installation problem

Hi
I do installation guide in Vaadin book(https://vaadin.com/book/-/page/getting-started.eclipse.html)
but when i Want to run codes there is a problem with imported file
eclipse can not resolved imported file
please help me
13196.jpg

Looks like Ivy has not fetched anything. Did you try right-clicking on your project and selecting Ivy → Resolve ?

resolved
tnx