As discussed with Rusty - The global configuration in the Jenkins interface is reporting “not found” errors for both the ElasticSearch URL and Port. I can connect to Elasticsearch from the command line on the Jenkins server to any one of the elasticsearch nodes in my cluster (using curl).

No user name or password is required but even after uninstalling and deleting all the plugins config files these fields are populate.

ERROR

HTTP ERROR 404

Problem accessing /configureTools/descriptorByName/LogstashInstallation/checkHost. Reason:

    Not Found
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ERROR

HTTP ERROR 404

Problem accessing /configureTools/descriptorByName/LogstashInstallation/checkInteger. Reason:

    Not Found

java version "1.7.0_101"

The Jenkins version from the config file is:
<version>2.11</version>

The Logstash-plugin version is: 1.2.0