500 Servlet Exception

javax.servlet.ServletException: Class `jsp1' was not found in classpath.
Classes normally belong in /WEB-INF/classes.
	at com.caucho.server.http.Application.instantiateServlet(Application.java:3198)
	at com.caucho.server.http.Application.createServlet(Application.java:3104)
	at com.caucho.server.http.Application.loadServlet(Application.java:3065)
	at com.caucho.server.http.QServletConfig.loadServlet(QServletConfig.java:435)
	at com.caucho.server.http.Application.getFilterChainServlet(Application.java:2809)
	at com.caucho.server.http.Application.buildFilterChain(Application.java:2765)
	at com.caucho.server.http.Invocation.service(Invocation.java:313)
	at com.caucho.server.http.CacheInvocation.service(CacheInvocation.java:135)
	at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:253)
	at com.caucho.server.http.HttpRequest.handleConnection(HttpRequest.java:170)
	at com.caucho.server.TcpConnection.run(TcpConnection.java:139)
	at java.lang.Thread.run(Thread.java:662)

Ymailsever 4.0.56 (built Tue Feb 15 11:12:27 PST 2019)