# Elasticsearch Start up Problem **URL:** \ **Category:** Elasticsearch\ **Created:** [May 30, 2016, 1:05pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322 "2016-05-30T13:05:46Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 30, 2016, 1:05pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/1 "2016-05-30T13:05:46Z")
Hi, I recently installed Elasticsearch on my server - while starting I'm getting below exception: Exception in thread "main" java.lang.UnsupportedClassVersionError: org/elasticsearch/bootstrap/Elasticsearch : Unsupported major.minor version 51.0 I've setup JDK1.8 and done everything required: java -version java version "1.8.0\_60" Java(TM) SE Runtime Environment (build 1.8.0\_60-b27) Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode) echo $JAVA\_HOME /u01/apps/java/jdk1.8.0\_60 Appreciate your help to resolve this issue please. Thanks, Ariv ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 30, 2016, 1:30pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/2 "2016-05-30T13:30:35Z")
Hello Arivazhagan, Version 51.0 is java 7. So, this would happen if you are trying to run ES with java 6. Maybe you have a java 6 installation? If this is the case, then the elasticsearch startup script is picking up that version somehow... Cheers ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 4:52am UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/3 "2016-05-31T04:52:53Z")
Hi Thiago, Thanks for your response. I do have 3 versions Java 6, 7 and 8. I've set my JAVA\_HOME to point to Java8, guess I have to try removing other two versions of the Java. Again, does ES still run with Java 7??? Thanks ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 11:15am UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/4 "2016-05-31T11:15:00Z")
Hi Arivazhagan, Yes, elasticsearch requires java 1.7u55+. Please, check the support matrix for more information [https://www.elastic.co/support/matrix](https://www.elastic.co/support/matrix) Cheers ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 11:51am UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/5 "2016-05-31T11:51:26Z")
Hi, I've moved the other Java installations but still i'm getting the above error.. ☹ ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 12:05pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/6 "2016-05-31T12:05:41Z")
Hello, Did you "moved" or did you "removed"? What is your OS? How did you installed ES? Cheers ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 12:09pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/7 "2016-05-31T12:09:54Z")
I moved to other location, but still the JAVA\_HOME is pointing to JDK1.8 OS Version: 2.6.32-100.34.1.el6uek.x86\_64 GNU/Linux I downloaded ES latest version and unzipped and ran /bin/elasticsearch.. Even I created another thread for installation issue: [ES Installation Problem](https://discuss.elastic.co/t/es-installation-problem/51417) From my browser I tried launch: [http://IP:9200](http://IP:9200) - is not working By the way - I don't see any definitive guide installing ES on Linux, could you share if you have any (in fact I have to install full ELK stack) ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 12:14pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/8 "2016-05-31T12:14:29Z")
There are several ways of installing/running ES in Linux. If you want a more standard way, try using repositories: [https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-repositories.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-repositories.html) Cheers ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 12:33pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/9 "2016-05-31T12:33:37Z")
Thanks for spending time to reply my queries. This the latest when I tried to install it again: Package elasticsearch-1.3.9-1.noarch already installed and latest version Nothing to do [xxxxx@xxxxxxxx~]$ sudo service elasticsearch restart [sudo] password for ecomm: Stopping elasticsearch: [FAILED] Starting elasticsearch: [OK] [xxxxx@xxxxxxxx~]$ Exception in thread "main" java.lang.UnsupportedClassVersionError: org/elasticsearch/bootstrap/Elasticsearch : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:634) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:277) at java.net.URLClassLoader.access$000(URLClassLoader.java:73) at java.net.URLClassLoader$1.run(URLClassLoader.java:212) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:205) at java.lang.ClassLoader.loadClass(ClassLoader.java:321) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294) at java.lang.ClassLoader.loadClass(ClassLoader.java:266) Could not find the main class: org.elasticsearch.bootstrap.Elasticsearch. Program will exit. ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 12:41pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/10 "2016-05-31T12:41:21Z")
Run the following and paste the output here: `which java` ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 12:49pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/11 "2016-05-31T12:49:16Z")
> [@Thiago\_Souza](#): > > which java /u01/apps/java/jdk1.8.0\_60/bin/java ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 1:00pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/12 "2016-05-31T13:00:50Z")
That's the correct one. You could add the following to /etc/default/elasticsearch: `JAVA_HOME=/u01/apps/java/jdk1.8.0_60` If does not works, then one last shot is setting the above line as the first line in /etc/init.d/elasticsearch. If even that does not works, then something else is causing elasticsearch init scripts to select the java 6 installation somehow. Cheers ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 1:10pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/13 "2016-05-31T13:10:15Z")
No luck, have tried all the step. Do you suggest to "completely remove" other JDK versions and do a fresh ES installation? ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 1:12pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/14 "2016-05-31T13:12:05Z")
Either that or maybe docker, are you familiar with docker? ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 1:12pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/15 "2016-05-31T13:12:28Z")
Sorry, not heard about it.. ---
**Author:** ![thiago](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/thiago/32/32096_2.png) [@thiago](https://discuss.elastic.co/u/thiago)\ **Post date:** [May 31, 2016, 1:17pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/16 "2016-05-31T13:17:23Z")
See if you can follow this [https://docs.docker.com/engine/installation/linux/oracle/](https://docs.docker.com/engine/installation/linux/oracle/) Then, if you can successfully install docker, then run elasticsearch with the following: `docker run -d --net host elasticsearch` ---
**Author:** ![Arivazhagan\_Vaithili](https://avatars.discourse-cdn.com/v4/letter/a/ba9def/32.png) [@Arivazhagan\_Vaithili](https://discuss.elastic.co/u/Arivazhagan_Vaithili)\ **Post date:** [May 31, 2016, 1:17pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/18 "2016-05-31T13:17:58Z")
Ok - will check and let you know. Thanks again ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 10:47pm UTC](https://discuss.elastic.co/t/elasticsearch-start-up-problem/51322/19 "2017-07-05T22:47:37Z")