freemarker issue with spring 3.0 java.lang.IllegalAccessError

We have recently upgraded to spring 3.0 version. after this we started getting below error on all the freemarker pages. this works fine with spring 2.x We are using freemarker 2.3.6 on searching for this error i could see similar issues reported by others but no solution seems to be reported.

tried to access class freemarker.ext.servlet.AllHttpScopesHashModel from class org.springframework.web.servlet.view.freemarker.FreeMarkerView

java.lang.IllegalAccessError: tried to access class freemarker.ext.servlet.AllHttpScopesHashModel from class org.springframework.web.servlet.view.freemarker.FreeMarkerView
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.buildTemplateModel(FreeMarkerView.java:295)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:276)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:233)
at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1047)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:817)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:363)
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(ContextHandle开发者_开发问答r.java:766)

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Update FreeMarker. AllHttpScopesHashModel was made public after 2.3.6 (in 2006).