"Invalid byte tag in constant pool: 15" still looks like a Java version issue.
Could you check what version of Java started with "ps aux | grep tomcat" ?
On Wed, May 25, 2016 at 12:41 PM, Stéphane LASSIRE
<slassire(a)cesap.asso.fr> wrote:
  Hello Thomas,
 So I take a look of all messages between you and Mohamed.
 *1* I put Java 8
 root@CESAP-WIKI01:/var/log/tomcat7# java -version
 java version "1.8.0_91"
 Java(TM) SE Runtime Environment (build 1.8.0_91-b14)
 Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)
 *2* Put tuning for Java 8
 root@CESAP-WIKI01:/var/log/tomcat7# update-alternatives --config java
 Il existe 3 choix pour l'alternative java (qui fournit /usr/bin/java).
   Sélection   Chemin                                          Priorité  État
 ------------------------------------------------------------
 * 0            /usr/lib/jvm/java-8-oracle/jre/bin/java          1062
 mode a
   1            /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   1061
 mode m
   2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1051
 mode m
   3            /usr/lib/jvm/java-8-oracle/jre/bin/java          1062
 mode m
 -> new JDK to the JDK_DIRS variable in /etc/init.d/tomcat7
 JDK_DIRS="/usr/lib/jvm/default-java ${OPENJDKS} /usr/lib/jvm/java-6-openjdk
 /usr/lib/jvm/java-6-sun /usr/lib/jvm/java-7-oracle
 /usr/lib/jvm/java-8-oracle"
 -> Modification /etc/default/tomcat7
 JAVA_HOME=/usr/lib/jvm/java-8-oracle
 But at this time I git a blank page on browser and ythis kind of error in
 catalina :
 mai 25, 2016 12:34:02 PM org.apache.coyote.AbstractProtocol init
 INFOS: Initializing ProtocolHandler ["http-bio-8080"]
 mai 25, 2016 12:34:02 PM org.apache.catalina.startup.Catalina load
 INFOS: Initialization processed in 721 ms
 mai 25, 2016 12:34:02 PM org.apache.catalina.core.StandardService
 startInternal
 INFOS: Démarrage du service Catalina
 mai 25, 2016 12:34:02 PM org.apache.catalina.core.StandardEngine
 startInternal
 INFOS: Starting Servlet Engine: Apache Tomcat/7.0.28
 mai 25, 2016 12:34:02 PM org.apache.catalina.startup.HostConfig
 deployDescriptor
 INFOS: Déploiement du descripteur de configuration
 /etc/tomcat7/Catalina/localhost/xwiki.xml
 mai 25, 2016 12:34:07 PM org.apache.catalina.startup.ContextConfig
 processAnnotationsJar
 GRAVE: Unable to process Jar entry
 [jdk/nashorn/internal/objects/NativeString.class] from Jar
 [jar:file:/usr/lib/jvm/java-8-oracle/jre/lib/ext/nashorn.jar!/] for
 annotations
 org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag
 in constant pool: 15
 Error in localhost.2016...
 mai 25, 2016 12:34:37 PM org.apache.catalina.core.StandardWrapperValve
 invoke
 GRAVE: "Servlet.service()" pour la servlet action a généré une exception
 javax.servlet.UnavailableException: Cannot initialize RequestProcessor of
 class com.xpn.xwiki.web.XWikiRequestProcessor:
 java.lang.NullPointerException
         at
 org.apache.struts.action.ActionServlet.getRequestProcessor(ActionServlet.java:614)
 Not very simple to solve this time
 Sorry
 Cordialement
 Stéphane Lassire
 Chargé de l'informatique et de la communication
 Tél direct : 01 42 85 81 87
 Courriel : slassire(a)cesap.asso.fr
 -----Message d'origine-----
 De : users [mailto:users-bounces@xwiki.org] De la part de Thomas Mortagne
 Envoyé : mercredi 25 mai 2016 11:17
 À : XWiki Users
 Objet : Re: [xwiki-users] Error upgrading Debian
 8.1 requires Java 8 so you need to make sure you configure Tomcat to use it.
 Note: it's possible the JVM is explicitely set in
 /etc/default/tomact7 (in which case Tomcat won't use the default JVM).
 On Wed, May 25, 2016 at 11:03 AM, Stéphane LASSIRE <slassire(a)cesap.asso.fr>
 wrote:
  Hello all,
 I just start to make an upgrade from my Xwiki 7.1.2 release to the
 last debian version.
 I am running a Debian server, a Postgresql database and Tomcat 7.
 I ran apt commands without problem.
 But in the run of Tomcat I got a bunch of  errors in catalina.out and
 the url show an error page.
 Browser :
 Etat HTTP 404 - /xwiki
   _____
 type Rapport d''état
 message /xwiki
 description La ressource demandée (/xwiki) n'est pas disponible.
   _____
 Apache Tomcat/7.0.28
 Catalina.out
 INFOS: Starting Servlet Engine: Apache Tomcat/7.0.28
 mai 25, 2016 10:36:34 AM org.apache.catalina.startup.HostConfig
 deployDescriptor
 INFOS: Déploiement du descripteur de configuration
 /etc/tomcat7/Catalina/localhost/xwiki.xml
 mai 25, 2016 10:36:36 AM org.apache.catalina.startup.ContextConfig
 processAnnotationsJar
 GRAVE: Unable to process Jar entry
 [org/infinispan/commons/marshall/MarshallableFunctions$AbstractSetValu
 eIfPresentReturnBoolean.class]
 from Jar
 [jar:file:/usr/lib/xwiki/WEB-INF/lib/infinispan-commons-8.2.1.Final.ja
 r!/]
 for annotations
 org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid
 byte tag in constant pool: 18
                 at
 org.apache.tomcat.util.bcel.classfile.Constant.readConstant(Constant.j
 ava:131)
                 at
 org.apache.tomcat.util.bcel.classfile.ConstantPool.<init>(ConstantPool
 .java:60)
                 at
 org.apache.tomcat.util.bcel.classfile.ClassParser.readConstantPool(Cla
 ssParser.java:209)
                 at
 org.apache.tomcat.util.bcel.classfile.ClassParser.parse(ClassParser.ja
 va:119)
                 at
 org.apache.catalina.startup.ContextConfig.processAnnotationsStream(Con
 textConfig.java:2049)
                 at
 org.apache.catalina.startup.ContextConfig.processAnnotationsJar(Contex
 tConfig.java:1931)
                 at
 org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(Contex
 tConfig.java:1899)
                 at
 org.apache.catalina.startup.ContextConfig.processAnnotations(ContextCo
 nfig.java:1885)
                 at
 org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java
 :1281)
                 at
 org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig
 .java:855)
                 at
 org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig
 .java:346)
                 at
 org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(Lifecycle
 Support.java:119)
                 at
 org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBas
 e.java:90)
                 at
 org.apache.catalina.core.StandardContext.startInternal(StandardContext
 .java:5209)
                 at
 org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
                 at
 org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.
 java:899)
                 at
 org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875
 )
                 at
 org.apache.catalina.core.StandardHost.addChild(StandardHost.java:618)
                 at
 org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.jav
 a:650)
                 at
 org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig
 .java:1582)
                 at
 java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471
 )
                 at
 java.util.concurrent.FutureTask.run(FutureTask.java:262)
                 at
 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.j
 ava:1145)
                 at
 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.
 java:615)
                 at java.lang.Thread.run(Thread.java:745)
 + all others talking about inifispan
 Thanks for your help
 Stéphane
 Cordialement
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 Thomas Mortagne
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