

If you are using an external database, familiarise yourself with all known issues for your specific database.If you are using Confluence EAR-WAR edition, check Installing the Confluence EAR-WAR Edition to see if there is anything extra you will need to do to get Confluence running.A newer version of Confluence may have different requirements than the previous version. the database system, the operating system, the application server and so on) still complies with the Confluence System Requirements. (Each upgrade notes page is a 'child' of its respective release notes page.) If you are upgrading from a version of Confluence prior to 2.5.5, the upgrade notes information is located under a heading on the release notes pages. The upgrade notes pages for recent major versions of Confluence are accessible from the Upgrade Notes Overview page.

It is important to read these upgrade notes as there might be specific changes between Confluence versions that could affect your Confluence instance.
