Render portlet error

Hi exo platform list,

last month, a collaborator and I have deployed an exo platform V1.1.4 on a Tomcat 5.5.23, and it works well.
I'm trying to put it on an other Tomcat 5.5.23. I've just copied all the common/lib directory of tomcat, all the war files present in the webapps directory, and the temp directory, in order to have all we previously configured.
So both Tomcat are the same, but I get a render portlet error when I try to go on the ecm page. I don't really know what's happening, so if you can have a look at the stack trace to indicate me what is the problem, it will be a great help :)

Here is my stack trace (repeated around 10 times) :
[ERROR] eXo -  - [portlet] Render Portlet Error:  <java.lang.NullPointerException>java.lang.NullPointerException
        at org.exoplatform.services.portletcontainer.impl.PortletContainerDispatcher.dispatch(PortletContainerDispatcher.java:387)
        at org.exoplatform.services.portletcontainer.impl.PortletContainerDispatcher.process(PortletContainerDispatcher.java:329)
        at org.exoplatform.services.portletcontainer.impl.PortletContainerDispatcher.render(PortletContainerDispatcher.java:276)
        at org.exoplatform.services.portletcontainer.impl.PortletContainerServiceImpl.render(PortletContainerServiceImpl.java:122)
        at org.exoplatform.portal.faces.renderer.html.portlet.PortletRenderer.addPortletData(PortletRenderer.java:134)
        at org.exoplatform.portal.faces.renderer.html.portlet.PortletRenderer.encodeChildren(PortletRenderer.java:84)
        at org.exoplatform.portal.faces.component.UIComponentRenderCommand.execute(UIComponentRenderCommand.java:42)
        at org.exoplatform.container.component.ExecutionContext.executeNextUnit(ExecutionContext.java:26)
        at org.exoplatform.portal.faces.component.UIComponentRenderStatisticCommand.execute(UIComponentRenderStatisticCommand.java:27)
        at org.exoplatform.container.component.ExecutionContext.execute(ExecutionContext.java:20)
        at org.exoplatform.portal.faces.component.UIComponentCommandChain.renderComponent(UIComponentCommandChain.java:26)
        at org.exoplatform.portal.faces.component.UIPortalComponent.encodeChildren(UIPortalComponent.java:177)
        at org.exoplatform.portal.faces.renderer.BaseRenderer.renderChildFloatHorizontal(BaseRenderer.java:126)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:267)
        at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:197)
        at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
        at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:220)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.directive.Foreach.render(Foreach.java:166)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:70)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:172)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:70)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:172)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:89)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.Template.merge(Template.java:256)
        at org.exoplatform.portal.faces.renderer.html.container.ContainerRenderer.encodeChildren(ContainerRenderer.java:68)
        at org.exoplatform.portal.faces.component.UIComponentRenderCommand.execute(UIComponentRenderCommand.java:42)
        at org.exoplatform.container.component.ExecutionContext.executeNextUnit(ExecutionContext.java:26)
        at org.exoplatform.portal.faces.component.UIComponentRenderStatisticCommand.execute(UIComponentRenderStatisticCommand.java:27)
        at org.exoplatform.container.component.ExecutionContext.execute(ExecutionContext.java:20)
        at org.exoplatform.portal.faces.component.UIComponentCommandChain.renderComponent(UIComponentCommandChain.java:26)
        at org.exoplatform.portal.faces.component.UIPortalComponent.encodeChildren(UIPortalComponent.java:177)
        at org.exoplatform.portal.faces.renderer.BaseRenderer.renderChildFloatVertical(BaseRenderer.java:119)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:267)
        at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:197)
        at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
        at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:220)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.directive.Foreach.render(Foreach.java:166)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:70)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:172)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:89)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:172)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:89)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.Template.merge(Template.java:256)
        at org.exoplatform.portal.faces.renderer.html.container.ContainerRenderer.encodeChildren(ContainerRenderer.java:68)
        at org.exoplatform.portal.faces.component.UIComponentRenderCommand.execute(UIComponentRenderCommand.java:42)
        at org.exoplatform.container.component.ExecutionContext.executeNextUnit(ExecutionContext.java:26)
        at org.exoplatform.portal.faces.component.UIComponentRenderStatisticCommand.execute(UIComponentRenderStatisticCommand.java:27)
        at org.exoplatform.container.component.ExecutionContext.execute(ExecutionContext.java:20)
        at org.exoplatform.portal.faces.component.UIComponentCommandChain.renderComponent(UIComponentCommandChain.java:26)
        at org.exoplatform.portal.faces.component.UIPortalComponent.encodeChildren(UIPortalComponent.java:177)
        at org.exoplatform.velocity.directive.JSFRenderChildren.render(JSFRenderChildren.java:37)
        at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
        at org.apache.velocity.Template.merge(Template.java:256)
        at org.exoplatform.portal.faces.renderer.html.portal.PortalRenderer.encodeChildren(PortalRenderer.java:59)
        at org.exoplatform.portal.faces.component.UIComponentRenderCommand.execute(UIComponentRenderCommand.java:42)
        at org.exoplatform.container.component.ExecutionContext.executeNextUnit(ExecutionContext.java:26)
        at org.exoplatform.portal.faces.component.UIComponentRenderStatisticCommand.execute(UIComponentRenderStatisticCommand.java:27)
        at org.exoplatform.container.component.ExecutionContext.execute(ExecutionContext.java:20)
        at org.exoplatform.portal.faces.component.UIComponentCommandChain.renderComponent(UIComponentCommandChain.java:26)
        at org.exoplatform.portal.faces.component.UIPortalComponent.encodeChildren(UIPortalComponent.java:177)
        at org.exoplatform.portal.faces.application.ExoPortalViewHandler.renderView(ExoPortalViewHandler.java:80)
        at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
        at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
        at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.exoplatform.services.workflow.impl.jbpm.WorkflowFilterServiceImpl.doFilter(WorkflowFilterServiceImpl.java:51)
        at org.exoplatform.services.workflow.WorkflowFilter.doFilter(WorkflowFilter.java:61)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.exoplatform.portal.filter.ExoRequestFilter.doFilter(ExoRequestFilter.java:78)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
        at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:834)
        at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:640)
        at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1286)
        at java.lang.Thread.run(Thread.java:595)

Best regards,
Cédric B.