XWiki fails to start

[root@tjfserver XWiki]# ./start_xwiki.sh
Starting Jetty on port 8080, please wait...
2018-01-20 09:29:24.528:INFO::main: Logging initialized @235ms
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.jetty.start.Main.invokeMain(Main.java:321)
at org.eclipse.jetty.start.Main.start(Main.java:817)
at org.eclipse.jetty.start.Main.main(Main.java:112)
Caused by: java.lang.UnsupportedClassVersionError: org/xwiki/tools/jetty/listener/NotifyListener : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.eclipse.jetty.util.Loader.loadClass(Loader.java:86)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.nodeClass(XmlConfiguration.java:364)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:754)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1125)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:1030)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.call(XmlConfiguration.java:721)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:417)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:354)
at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:262)
at org.eclipse.jetty.xml.XmlConfiguration$1.run(XmlConfiguration.java:1243)
at java.security.AccessController.doPrivileged(Native Method)
at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1174)
... 7 more

Usage: java -jar start.jar [options] [properties] [configs]
java -jar start.jar --help # for more information
[root@tjfserver XWiki]#

as i am not fluent in java, i have no idea what is wrong, or how to fix it.