# ElasticSearch 1.2.1 doesnt run on JDK 1.6? **URL:** \ **Category:** Elasticsearch\ **Created:** [July 2, 2014, 2:21pm UTC](https://discuss.elastic.co/t/elasticsearch-1-2-1-doesnt-run-on-jdk-1-6/18443 "2014-07-02T14:21:52Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![David\_Marko](https://avatars.discourse-cdn.com/v4/letter/d/ba8739/32.png) [@David\_Marko](https://discuss.elastic.co/u/David_Marko)\ **Post date:** [July 2, 2014, 2:21pm UTC](https://discuss.elastic.co/t/elasticsearch-1-2-1-doesnt-run-on-jdk-1-6/18443/1 "2014-07-02T14:21:52Z")
We have been using older Elasticsearch version here upgrading to 1.2.1 shows use 'unknown class version errors' on JDK 1.6 . Docs says that JDK 1.6 is support (and it was) . Is there some update here? What latest Elasticsearch version is available fo JDK 1.6? -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/a5df4ed1-6dd4-4402-8208-25d35c27ca49%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a5df4ed1-6dd4-4402-8208-25d35c27ca49%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![jprante](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jprante/32/44941_2.png) [@jprante](https://discuss.elastic.co/u/jprante)\ **Post date:** [July 2, 2014, 2:25pm UTC](https://discuss.elastic.co/t/elasticsearch-1-2-1-doesnt-run-on-jdk-1-6/18443/2 "2014-07-02T14:25:31Z")
Docs say at least Java 7 is required from ES 1.2.0 on > **[Elasticsearch Platform — Find real-time answers at scale](https://www.elastic.co)** > > Power insights and outcomes with the Elasticsearch Platform and AI. See into your data and find answers that matter with enterprise solutions designed to help you build, observe, and protect. Try Elasticsearch free today. For Java 6, you have to use ES versions \< 1.2.0 Jörg On Wed, Jul 2, 2014 at 4:21 PM, David Marko [dmarko484@gmail.com](mailto:dmarko484@gmail.com) wrote: > We have been using older Elasticsearch version here upgrading to 1.2.1 > shows use 'unknown class version errors' on JDK 1.6 . Docs says that JDK > 1.6 is support (and it was) . Is there some update here? What latest > Elasticsearch version is available fo JDK 1.6? > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/a5df4ed1-6dd4-4402-8208-25d35c27ca49%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a5df4ed1-6dd4-4402-8208-25d35c27ca49%40googlegroups.com) > [https://groups.google.com/d/msgid/elasticsearch/a5df4ed1-6dd4-4402-8208-25d35c27ca49%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/a5df4ed1-6dd4-4402-8208-25d35c27ca49%40googlegroups.com?utm_medium=email&utm_source=footer) > . > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAKdsXoHCmOPogq7ZCvA%3DcacYUMyE0qCHsxVN4cCk%3DhfE67FpDQ%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAKdsXoHCmOPogq7ZCvA%3DcacYUMyE0qCHsxVN4cCk%3DhfE67FpDQ%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 1:18am UTC](https://discuss.elastic.co/t/elasticsearch-1-2-1-doesnt-run-on-jdk-1-6/18443/3 "2017-07-06T01:18:22Z")