Upgrading DS/OpenDJ (All versions) fails with UnsupportedClassVersion error

Last updated Nov 2, 2020

The purpose of this article is to provide assistance if the DS/OpenDJ server fails to upgrade to a later version with "Exception in thread "main" java.lang.UnsupportedClassVersionError".


An error similar to the following is shown when the upgrade fails:

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/opends/server/tools/upgrade/UpgradeCli : Unsupported major.minor version 52.0   at java.lang.ClassLoader.defineClass1(Native Method)   at java.lang.ClassLoader.defineClass(   at   at   at$100(   at$   at$   at Method)   at   at java.lang.ClassLoader.loadClass(   at sun.misc.Launcher$AppClassLoader.loadClass(   at java.lang.ClassLoader.loadClass(   at sun.launcher.LauncherHelper.checkAndLoadMain(

The same error is shown in the Upgrade.log file.

Recent Changes



The version of DS/OpenDJ you are upgrading to requires a different version of Java® than the one running on your server. The Java versions required are as follows:

  • DS 7 - Java 11
  • DS 6.5.x - Java 8 or 11
  • DS 6 - Java 8 or 9
  • DS 5.5.x - Java 8
  • DS 5 - Java 7 or 8
  • OpenDJ 3.x - Java 7 or 8

See the release notes applicable to your version for further information, for example: DS 7 Release Notes › Java.


This issue can be resolved by installing the required version of Java and then enabling the server to use the newer version as detailed in How do I change DS/OpenDJ (All versions) to use a different JDK version?

Once Java is successfully updated, you can then upgrade the DS/OpenDJ server.

See Also

How do I ensure DS/OpenDJ (All versions) uses the Java settings from file when starting?

Upgrading DS/OpenDJ

Upgrade Guide

Related Training


Related Issue Tracker IDs


Copyright and TrademarksCopyright © 2020 ForgeRock, all rights reserved.