我正在开发一个网络应用程序并收到此错误但无法理解（我已经查看了类似的问题，但那里的答案似乎并不适用于我的问题） 任何人都可以理解这个吗？ 请帮帮我。
[WARN] Exception while dispatching incoming RPC call
java.lang.ClassCastException: java.lang.NoClassDefFoundError cannot be cast to java.lang.Exception
at net.sf.gilead.gwt.PersistentRemoteService.processCall(PersistentRemoteService.java:177)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:373)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:755)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:686)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1494)
at org.realityforge.gwt.cache_filter.GWTGzipFilter.doFilter(GWTGzipFilter.java:57)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
at ... (more eclipse.jetty...)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
at java.lang.Thread.run(Thread.java:748)
[ERROR] 500 - POST /webproj/login (127.0.0.1) 57 bytes
Request headers
Host: (...)
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: text/x-gwt-rpc; charset=utf-8
(leaving some stuff out)
Connection: keep-alive
Response headers
Content-Type: text/plain