java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.validator.engine.ConfigurationImpl

[Y2i]

When I place hibernate-validator-4.1.0.Final.jar to WEB-INF/lib and
start my app, I'm getting a strange error when inserting a new entity
into the database. org.hibernate.validator.HibernateValidator and
org.hibernate.validator.engine.ConfigurationImpl are in the same jar,
namely in hibernate-validator-4.1.0.Final.jar, but for some reason
there is no definition for
org.hibernate.validator.engine.ConfigurationImpl.

I would really appreciate it if someone could please help me solve
this puzzle.

java.lang.NoClassDefFoundError: Could not initialize class
org.hibernate.validator.engine.ConfigurationImpl
at
org.hibernate.validator.HibernateValidator.createGenericConfiguration(HibernateValidator.java:
43)
at javax.validation.Validation
$GenericBootstrapImpl.configure(Validation.java:269)
at
javax.validation.Validation.buildDefaultValidatorFactory(Validation.java:
111)
at
com.google.gwt.requestfactory.server.JsonRequestProcessor.getEntityDataForRecord(JsonRequestProcessor.java:
440)
at
com.google.gwt.requestfactory.server.JsonRequestProcessor.constructAfterDvsDataMap(JsonRequestProcessor.java:
811)
at
com.google.gwt.requestfactory.server.JsonRequestProcessor.processJsonRequest(JsonRequestProcessor.java:
690)
at
com.google.gwt.requestfactory.server.JsonRequestProcessor.decodeAndInvokeRequest(JsonRequestProcessor.java:
177)
at
com.google.gwt.requestfactory.server.JsonRequestProcessor.decodeAndInvokeRequest(JsonRequestProcessor.java:
56)
at
com.google.gwt.requestfactory.server.RequestFactoryServlet.doPost(RequestFactoryServlet.java:
87)
at
com.mytestpackage.server.MyRequestFactoryServlet.doPost(MyRequestFactoryServlet.java:
42)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:
487)
at
org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:
362)
at
org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:
216)
at
org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:
181)
at
org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:
729)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:
405)
at
org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
152)
at
org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:
49)
at
org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:
505)
at org.mortbay.jetty.HttpConnection
$RequestHandler.content(HttpConnection.java:843)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at
org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:
395)
at org.mortbay.thread.QueuedThreadPool
$PoolThread.run(QueuedThreadPool.java:488)