It looks to me like you were trying to run something in Tomcat. So your project's build path is not especially relevant to that.
So presumably that class wasn't exported as part of the web app which you're trying to run in Tomcat. I don't know how Eclipse is getting hold of that error message either; I would recommend running Tomcat as a separate instance, rather than having one which is confusingly entangled with Eclipse, and deploy your project to it as a WAR.
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