@11:45:07#~# java -jar /usr/share/mediathekview/MediathekView.jar -autofast
___  ___         _ _       _   _          _    _   _ _
|  \/  |        | (_)     | | | |        | |  | | | (_)
| .  . | ___  __| |_  __ _| |_| |__   ___| | _| | | |_  _____      __
| |\/| |/ _ \/ _` | |/ _` | __| '_ \ / _ \ |/ / | | | |/ _ \ \ /\ / /
| |  | |  __/ (_| | | (_| | |_| | | |  __/   <\ \_/ / |  __/\ V  V /
\_|  |_/\___|\__,_|_|\__,_|\__|_| |_|\___|_|\_\\___/|_|\___| \_/\_/

. Startparameter: -autofast
. Portable Mode: false
Exception in thread "main" java.lang.NoClassDefFoundError: javafx/concurrent/Task
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at mediathek.Main.setupPortableMode(Main.java:149)
        at mediathek.Main.main(Main.java:158)
Caused by: java.lang.ClassNotFoundException: javafx.concurrent.Task
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 14 more

Hier die Java-Installation, an der sich meines Wissens nichts geändert hat!

@11:44:05#~# aptitude search '~S ~i openjdk '
i   openjdk-7-jdk                   - Werkzeugsatz für die Entwicklung mit OpenJDK (JDK)
i A openjdk-7-jre                   - OpenJDK-Java-Laufzeitumgebung, verwendet Hotspot JIT
i A openjdk-7-jre-headless          - OpenJDK-Java-Laufzeitumgebung, verwendet Hotspot JIT (ohne GUI)
i   openjdk-8-dbg                   - Java runtime based on OpenJDK (debugging symbols)
i   openjdk-8-jdk                   - OpenJDK Development Kit (JDK)
i A openjdk-8-jdk-headless          - OpenJDK Development Kit (JDK) (headless)
i   openjdk-8-jre                   - OpenJDK Java runtime, using Hotspot JIT
i A openjdk-8-jre-headless          - OpenJDK Java runtime, using Hotspot JIT (headless)

@12:13:37#~# apt --installed list | grep openjdk
openjdk-7-jdk/oldstable,now 7u181-2.6.14-2~deb8u1 amd64  [installiert]
openjdk-7-jre/oldstable,now 7u181-2.6.14-2~deb8u1 amd64  [Installiert,automatisch]
openjdk-7-jre-headless/oldstable,now 7u181-2.6.14-2~deb8u1 amd64  [Installiert,automatisch]
openjdk-8-dbg/jessie-backports,now 8u171-b11-1~bpo8+1 amd64  [installiert]
openjdk-8-jdk/jessie-backports,now 8u171-b11-1~bpo8+1 amd64  [installiert]
openjdk-8-jdk-headless/jessie-backports,now 8u171-b11-1~bpo8+1 amd64  [Installiert,automatisch]
openjdk-8-jre/jessie-backports,now 8u171-b11-1~bpo8+1 amd64  [installiert]
openjdk-8-jre-headless/jessie-backports,now 8u171-b11-1~bpo8+1 amd64  [Installiert,automatisch]

@11:33:53#~# update-alternatives --config java
Es gibt 2 Auswahlmöglichkeiten für die Alternative java (welche /usr/bin/java bereitstellen).

  Auswahl      Pfad                                            Priorität Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      automatischer Modus
  1            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      manueller Modus
* 2            /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java   1069      manueller Modus

Hat jemand eine Idee wie ich mein Problem lösen kann?