[Leonatus]

I now tried to upgrade the desktop version of LanguageTool to 6.6, the LanguageTool beeing 0.4.3. Sigil v. 2.5.2, Windows 10, 64 bit. I changed the entries in the .json file to the respective folder of the LanguageTool 6.6.
Before running the tool, I updated the Java version to 8, update 451.
But then, I got the message:

Status: failed

Working on chapter.xhtml...
EPUBCheck Java error.
 Exception in thread "main" java.lang.UnsupportedClassVersionError: org/languagetool/commandline/Main has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 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$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

What, please, do I have to do?