Upgrade Notes Overview
Typically, each major release of Confluence comes with upgrade notes, which are specific recommendations for upgrading from the previous major version. If you plan to upgrade and skip a few Confluence versions, you must read the upgrade notes for all major versions between your current version and the version to which you are upgrading, to make sure you do not miss something important.
Please read our general information about upgrading Confluence.
When upgrading from Confluence 5.3 to Confluence 5.5, read the upgrade notes for Confluence 5.4, as well as those for Confluence 5.5.
Also, we strongly recommend that you read the upgrade notes for any minor releases in-between, since they contain important information that will affect your Confluence upgrade.
Before installing an add-on (also called a plugin) into your Confluence site, please check the add-on's information page to see whether it is supported by Atlassian, by another vendor, or not at all. See our guidelines on add-on support.