(supposé) problème JASPER

Bonjour, lorsque je clique sur un lien (dont j'ai vraiment besoin, il s'agit d'une inscription à l'université), voilà ce qui s'affiche dans la fenetre :
Erreur lors de la génération du PDF. (probleme JASPER)

java.io.FileNotFoundException: /appli/ac-paris/aglae3/conf/jasper/null.jasper
at dori.jasper.engine.util.JRLoader.loadObject(Ljava/io/File;)Ljava/lang/Object;(JRLoader.java:117)
at dori.jasper.engine.JasperFillManager.fillReport(Ljava/lang/String;Ljava/util/Map;Ljava/sql/Connection;)Ldori/jasper/engine/JasperPrint;(JasperFillManager.java:160)
at dori.jasper.engine.JasperRunManager.runReportToPdf(Ljava/lang/String;Ljava/util/Map;Ljava/sql/Connection;)[B(JasperRunManager.java:168)
at fr.edu.paris.aglae3.web.servlet.PdfServlet.doGet(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(Unknown Source)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run()Ljava/lang/Object;(ServletStubImpl.java:1072)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;Lweblogic/servlet/internal/FilterChainImpl;)V(ServletStubImpl.java:465)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(ServletStubImpl.java:348)
at weblogic.servlet.internal.RequestDispatcherImpl.forward(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(RequestDispatcherImpl.java:322)
at fr.edu.paris.aglae3.web.suivi.controleur.DispatchSuivi.doNotif(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(Unknown Source)
at fr.edu.paris.aglae3.web.suivi.controleur.DispatchSuivi.doGet(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(Unknown Source)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run()Ljava/lang/Object;(ServletStubImpl.java:1072)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;Lweblogic/servlet/internal/FilterChainImpl;)V(ServletStubImpl.java:465)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(ServletStubImpl.java:348)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run()Ljava/lang/Object;(WebAppServletContext.java:6981)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(Lweblogic/security/subject/AbstractSubject;Ljava/security/PrivilegedAction;)Ljava/lang/Object;(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(Lweblogic/security/acl/internal/AuthenticatedSubject;Lweblogic/security/acl/internal/AuthenticatedSubject;Ljava/security/PrivilegedAction;)Ljava/lang/Object;(SecurityManager.java:121)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(Lweblogic/servlet/internal/ServletRequestImpl;Lweblogic/servlet/internal/ServletResponseImpl;)V(WebAppServletContext.java:3892)
at weblogic.servlet.internal.ServletRequestImpl.execute(Lweblogic/kernel/ExecuteThread;)V(ServletRequestImpl.java:2766)
at weblogic.kernel.ExecuteThread.execute(Lweblogic/kernel/ExecuteRequest;)V(ExecuteThread.java:224)
at weblogic.kernel.ExecuteThread.run()V(ExecuteThread.java:183)
at java.lang.Thread.startThreadFromVM(Ljava/lang/Thread;)V(Unknown Source)

NESTED BY :
dori.jasper.engine.JRException: /appli/ac-paris/aglae3/conf/jasper/null.jasper
at dori.jasper.engine.util.JRLoader.loadObject(Ljava/io/File;)Ljava/lang/Object;(JRLoader.java:117)
at dori.jasper.engine.JasperFillManager.fillReport(Ljava/lang/String;Ljava/util/Map;Ljava/sql/Connection;)Ldori/jasper/engine/JasperPrint;(JasperFillManager.java:160)
at dori.jasper.engine.JasperRunManager.runReportToPdf(Ljava/lang/String;Ljava/util/Map;Ljava/sql/Connection;)[B(JasperRunManager.java:168)
at fr.edu.paris.aglae3.web.servlet.PdfServlet.doGet(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(Unknown Source)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run()Ljava/lang/Object;(ServletStubImpl.java:1072)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;Lweblogic/servlet/internal/FilterChainImpl;)V(ServletStubImpl.java:465)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(ServletStubImpl.java:348)
at weblogic.servlet.internal.RequestDispatcherImpl.forward(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(RequestDispatcherImpl.java:322)
at fr.edu.paris.aglae3.web.suivi.controleur.DispatchSuivi.doNotif(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(Unknown Source)
at fr.edu.paris.aglae3.web.suivi.controleur.DispatchSuivi.doGet(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(Unknown Source)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run()Ljava/lang/Object;(ServletStubImpl.java:1072)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;Lweblogic/servlet/internal/FilterChainImpl;)V(ServletStubImpl.java:465)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;)V(ServletStubImpl.java:348)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run()Ljava/lang/Object;(WebAppServletContext.java:6981)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(Lweblogic/security/subject/AbstractSubject;Ljava/security/PrivilegedAction;)Ljava/lang/Object;(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(Lweblogic/security/acl/internal/AuthenticatedSubject;Lweblogic/security/acl/internal/AuthenticatedSubject;Ljava/security/PrivilegedAction;)Ljava/lang/Object;(SecurityManager.java:121)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(Lweblogic/servlet/internal/ServletRequestImpl;Lweblogic/servlet/internal/ServletResponseImpl;)V(WebAppServletContext.java:3892)
at weblogic.servlet.internal.ServletRequestImpl.execute(Lweblogic/kernel/ExecuteThread;)V(ServletRequestImpl.java:2766)
at weblogic.kernel.ExecuteThread.execute(Lweblogic/kernel/ExecuteRequest;)V(ExecuteThread.java:224)
at weblogic.kernel.ExecuteThread.run()V(ExecuteThread.java:183)
at java.lang.Thread.startThreadFromVM(Ljava/lang/Thread;)V(Unknown Source)
Caused by: java.io.FileNotFoundException: /appli/ac-paris/aglae3/conf/jasper/null.jasper
... 25 more