My version is 6.2.1.
I added "xpack.notification.email.html.sanitization.enabled: false" to elasticsearch.yml but I can not run elasticsearch successfully after adding that line.
Caused by: java.lang.IllegalArgumentException: unknown setting [xpack.notification.email.html.sanitization.enabled] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:346) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:310) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:284) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.common.settings.SettingsModule.<init>(SettingsModule.java:134) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.node.Node.<init>(Node.java:331) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.node.Node.<init>(Node.java:246) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:213) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:213) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:323) ~[elasticsearch-6.2.1.jar:6.2.1]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121) ~[elasticsearch-6.2.1.jar:6.2.1]
... 6 more