Hi Michela,
thanks for your suggestion.
I've run the Find Model Problem option but that don't return any error.
My web application is the same as in this guide:
https://my.webratio.com/learn/learningobject/your-first-web-application-v-72?link=oln72ae.redirect&nav=14#!ajax=true
but I can't run it and deploy it on Tomcat.