java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)

Stop Tomcat (if it's running)
Open the "Servers" view: Window > Show view > Other > Server > Servers
Right Click on Tomcat Server > Clean Tomcat Work Directory.
Right Click on Tomcat Server > Clean
Restart the server