Downgrade from 5.0.0-alpha to 2.4.1 Fails

Installed 5.0.0-alpha on CentOS 7 (VirtualBox) which worked ok but I had some issues with the JAVA API documentation. Tried to downgrade to 2.4.1 and when ES starts I get the following error (appears on the cluster log file:

[2016-10-14 09:40:11,830][INFO ][node                     ] [kobi-node] version[2.4.1], pid[4420], bui
[2016-10-14 09:40:11,848][INFO ][node                     ] [kobi-node] initializing ...
[2016-10-14 09:40:11,862][ERROR][bootstrap                ] Exception
java.lang.IllegalStateException: Unable to initialize modules
	at org.elasticsearch.plugins.PluginsService.<init>(
	at org.elasticsearch.node.Node.<init>(
	at org.elasticsearch.node.Node.<init>(
	at org.elasticsearch.bootstrap.Bootstrap.setup(
	at org.elasticsearch.bootstrap.Bootstrap.init(
	at org.elasticsearch.bootstrap.Elasticsearch.main(
Caused by: java.nio.file.NoSuchFileException: /usr/share/elasticsearch/modules/aggs-matrix-stats/plugi
	at sun.nio.fs.UnixException.translateToIOException(
	at sun.nio.fs.UnixException.rethrowAsIOException(
	at sun.nio.fs.UnixException.rethrowAsIOException(
	at sun.nio.fs.UnixFileSystemProvider.newByteChannel(
	at java.nio.file.Files.newByteChannel(
	at java.nio.file.Files.newByteChannel(
	at java.nio.file.spi.FileSystemProvider.newInputStream(
	at java.nio.file.Files.newInputStream(
	at org.elasticsearch.plugins.PluginInfo.readFromProperties(
	at org.elasticsearch.plugins.PluginsService.getModuleBundles(
	at org.elasticsearch.plugins.PluginsService.<init>(
	... 6 more

I tried to list my plugins and there are none. Also both "modules" and "plugins" folders are empty under /usr/share/elasticsearch. Any ideas?


Reinstall completely a fresh new version You can not downgrade.

Here internal modules 5.0 are not compatible with modules 2.x.


can you uninstall the 5.0 version AND delete the /usr/share/elasticsearch/modules/ directory by hand. Then install 2.4 - seems there are some leftover from 5.0...


Thanks for the tip.
Decided to uninstall and remove any relevant leftover folders altogether. Then re-installed 2.4.1 - Seems to do the trick.