Installing Add-on Gets stuck and throws Unsupported major.minor version 52.0
Platform Notice: Data Center Only - This article only applies to Atlassian products on the Data Center platform.
Note that this KB was created for the Data Center version of the product. Data Center KBs for non-Data-Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Summary
Problem
When installing and add-on, it gets stuck using the UI.
The following appears in the atlassian-bitbucket.log:
1
2
3
4
5
6
7
8
9
10
11
12
2015-12-08 08:50:39,489 ERROR [ThreadPoolAsyncTaskExecutor::Thread 32] Adam @27RGFBx530x321784x0 1f0e1cf 172.29.139.22 "POST /rest/plugins/1.0/ HTTP/1.1" c.a.plugin.osgi.factory.OsgiPlugin Unable to start the plugin container for plugin 'com.palantir.stash.stashbot'
org.springframework.beans.factory.CannotLoadBeanClassException: Error loading class [com.palantir.stash.stashbot.outputhandler.CommandOutputHandlerFactory] for bean with name 'commandOutputHandlerFactory' defined in URL [bundle://99.0:0/META-INF/spring/atlassian-plugins-components.xml]: problem with class file or dependent class; nested exception is java.lang.UnsupportedClassVersionError: com/palantir/stash/stashbot/outputhandler/CommandOutputHandlerFactory : Unsupported major.minor version 52.0
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1144) ~[spring-beans-4.1.4.RELEASE.jar:4.1.4.RELEASE]
...
Caused by: java.lang.UnsupportedClassVersionError: com/palantir/stash/stashbot/outputhandler/CommandOutputHandlerFactory : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.7.0_65]
...
2015-12-08 08:50:39,493 ERROR [ThreadPoolAsyncTaskExecutor::Thread 32] Adam @27RGFBx530x321784x0 1f0e1cf 172.29.139.22 "POST /rest/plugins/1.0/ HTTP/1.1" o.s.o.e.i.a.ContextLoaderListener Application context refresh failed (NonValidatingOsgiBundleXmlApplicationContext(bundle=com.palantir.stash.stashbot, config=osgibundle:/META-INF/spring/*.xml))
org.springframework.beans.factory.CannotLoadBeanClassException: Error loading class [com.palantir.stash.stashbot.outputhandler.CommandOutputHandlerFactory] for bean with name 'commandOutputHandlerFactory' defined in URL [bundle://99.0:0/META-INF/spring/atlassian-plugins-components.xml]: problem with class file or dependent class; nested exception is java.lang.UnsupportedClassVersionError: com/palantir/stash/stashbot/outputhandler/CommandOutputHandlerFactory : Unsupported major.minor version 52.0
...
Caused by: java.lang.UnsupportedClassVersionError: com/palantir/stash/stashbot/outputhandler/CommandOutputHandlerFactory : Unsupported major.minor version 52.0
...Diagnosis
Diagnostic Steps
As described on the Stashbot - versions website (
com.palantir.stash.stashboton the stack trace above), the add-on requires you to be running on Java 8.
Cause
Unsupported major.minor version 52.0
This means that you're trying to run a code that was compiled in Java 8 on a Java 7 JRE.
Solution
Resolution
Make sure your release of Stash or Bitbucket Server supports Java 8. Please refer to the Supported platforms document for your release before upgrading.
Reinstall the add-on usin UPM once your new Stash or Bitbucket Server is up and running
Was this helpful?