始める前に

• Check your Confluence licence is valid.
  To check go to  > Atlassian Support Tools > Health Check and make sure the license support period has not expired. If your support period has expired renew your licence and reapply it before proceeding with the upgrade.

• Read the Release Notes and Upgrade Notes for both the version you are upgrading to, and any versions you are skipping.

• Check that your Java version, application server, operating system, database and browsers are supported. 
  See Supported Platforms and End of Support Announcements for Confluence to confirm latest requirements.

• Check the latest database setup guide for your database and ensure that the database is configured correctly. There may be new configuration requirements. See Database Configuration.

• Check the compatibility of any add-ons.
  Some add-ons may not yet be compatible with the latest version of Confluence. See Checking app compatibility with application updates to find out how to check this in the Universal Plugin Manager.

• Check for any known issues that might affect your instance.
  See the Confluence Knowledge Base for known issues for the version you are upgrading to and Database Troubleshooting for known issues related to supported external databases.

• Confluence に施した修正は記録しておいてください（例えば、レイアウト、カスタムテーマ）。
  カスタマイズを維持するには、アップグレード後に再度適用する必要があります。