DFC_SESSION_DUPLICATE_IDENTITY

Since we have D2 updated to version v4.2.0100 Build 515, we get on a regular basis the following message"[DFC_SESSION_DUPLICATE_IDENTITY] An identity is already defined for docbase ".........""

the logfile doesn't help me much.

[DFC_SESSION_DUPLICATE_IDENTITY] An identity is already defined for docbase ".............."

        at com.emc.d2fs.dctm.aspects.InjectSessionAspect.process(InjectSessionAspect.java:152) [D2FS4DCTM-WEB-4.2.0.jar!/:na]

        at com.emc.d2fs.dctm.web.services.download.D2DownloadService.getDownloadUrls(D2DownloadService.java:736) [D2FS4DCTM-WEB-4.2.0.jar!/:na]

        at com.emc.x3.server.services.RpcPDFViewerServiceImpl.getDownloadUrls(RpcPDFViewerServiceImpl.java:31) [D2-PDFViewer-4.2.0.jar!/:na]

        at sun.reflect.GeneratedMethodAccessor392.invoke(Unknown Source) [na:na]

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_45]

        at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_45]

        at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:561) [gwt-servlet-2.5.1.jar!/:na]

        at com.emc.x3.server.GuiceRemoteServiceServlet.processCall(GuiceRemoteServiceServlet.java:105) [X3-Common-4.2.0.jar!/:na]

        at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248) [gwt-servlet-2.5.1.jar!/:na]

        at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) [gwt-servlet-2.5.1.jar!/:na]

        at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) [servlet-api.jar!/:na]

        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) [servlet-api.jar!/:na]

Is there someone who can help me with this problem