Problem selecting Java Version / "empty" application list

Technical Support
1

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OS Name/Version: Debian 9

Product Name/Version: (Always use the full version number - not ‘Latest’) 2.4.0.4

Problem Description:
When starting a MC instance the error message about using the wrong Java Version gets displayed. However I do not find any way to change the version on the Options/Settings

:Anonymous14:30:30
Failure to make API call to MC101 (http://127.0.0.1:8081/API/Core/GetAPISpec) - retried 10 times : Connection refused
HttpRequestException
[0] (HttpRequestException) : Connection refused
at ADSModule.WebMethods.MakeInstanceRequest (m.Http.IHttpRequest request, String REQ_RAWJSON, String requesturi) at ADSModule.WebMethods.Servers (m.Http.IHttpRequest request, String id, String REQ_RAWJSON)
SocketException
[1] (SocketException) : Connection refused

14:44:06
at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:601)
14:44:09
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: net/minecraft/bundler/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(ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:601)
14:44:14
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: net/minecraft/bundler/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(ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:601)

Steps to reproduce:

  • Step 1: Created Java MC instance
  • Step 2: tried to start the instance
  • Step 3: looked for the Java options

Actions taken to resolve so far:

  • restarting AMP
  • updating it
  • reapplied the license

Also, when creating new instances it takes a while until all applications appear in the drop down list

2

Hi Marco,

check your installation of Java in your Debian with update-alternatives.

Just in case I suggest you to install TEMURIN 17 (you don’t have write your java version), and if missing on your repository just add them with:

wget -O - https://packages.adoptium.net/artifactory/api/gpg/key/public | apt-key add -

echo "deb https://packages.adoptium.net/artifactory/deb $(awk -F= '/^VERSION_CODENAME/{print$2}' /etc/os-release) main" | tee /etc/apt/sources.list.d/adoptium.list

apt-get update && apt-get install temurin-17-jdk

restart your machine, and after that check if all working properly, and setup your instance to use this version of java. Have fun :slight_smile:

Cheers

Ivo

3

Thank you so much. This helped to fix the issue!

1 Like