Console Output

Established TCP socket on 40591
Exception in thread "main" java.lang.UnsupportedClassVersionError: hudson/remoting/Launcher : Unsupported major.minor version 52.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
	at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
	at jenkins.maven3.agent.Maven33Main.main(Maven33Main.java:133)
	at jenkins.maven3.agent.Maven33Main.main(Maven33Main.java:64)
Established TCP socket on 51451
<===[JENKINS REMOTING CAPACITY]===>channel started
Executing Maven:  -B -f /var/lib/jenkins/jobs/guilib/workspace/pom.xml -Dmaven.repo.local=/var/lib/jenkins/maven-repositories/0 deploy -Panon-cc-dev
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building guilib 00.00.224-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] Downloading: http://svn.jondos.de/maven/repos/anon/anonlib/00.20.022-SNAPSHOT/maven-metadata.xml
[INFO] Downloading: http://anon.inf.tu-dresden.de/artifactory/repo/anon/anonlib/00.20.022-SNAPSHOT/maven-metadata.xml
[WARNING] Could not transfer metadata anon:anonlib:00.20.022-SNAPSHOT/maven-metadata.xml from/to jondos.repos.http (http://svn.jondos.de/maven/repos): Connect to svn.jondos.de:80 [svn.jondos.de/78.129.167.102] failed: Verbindungsaufbau abgelehnt (Connection refused)
[WARNING] Failure to transfer anon:anonlib:00.20.022-SNAPSHOT/maven-metadata.xml from http://svn.jondos.de/maven/repos was cached in the local repository, resolution will not be reattempted until the update interval of jondos.repos.http has elapsed or updates are forced. Original error: Could not transfer metadata anon:anonlib:00.20.022-SNAPSHOT/maven-metadata.xml from/to jondos.repos.http (http://svn.jondos.de/maven/repos): Connect to svn.jondos.de:80 [svn.jondos.de/78.129.167.102] failed: Verbindungsaufbau abgelehnt (Connection refused)
[INFO] Downloading: http://anon.inf.tu-dresden.de/artifactory/repo/anon/anonlib/00.20.022-SNAPSHOT/anonlib-00.20.022-SNAPSHOT.pom
[INFO] Downloading: http://svn.jondos.de/maven/repos/anon/anonlib/00.20.022-SNAPSHOT/anonlib-00.20.022-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5.984 s
[INFO] Finished at: 2017-09-22T17:46:57+02:00
[INFO] Final Memory: 10M/110M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project guilib: Could not resolve dependencies for project anon:guilib:jar:00.00.224-SNAPSHOT: Failed to collect dependencies at anon:anonlib:jar:00.20.022-SNAPSHOT: Failed to read artifact descriptor for anon:anonlib:jar:00.20.022-SNAPSHOT: Could not transfer artifact anon:anonlib:pom:00.20.022-SNAPSHOT from/to jondos.repos.http (http://svn.jondos.de/maven/repos): Connect to svn.jondos.de:80 [svn.jondos.de/78.129.167.102] failed: Verbindungsaufbau abgelehnt (Connection refused) -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException