Problem

The Documentation theme is broken, and the left navigation bar is missing post-Confluence upgrade

Cause

The wrong documentation theme plugin is loaded (instead of the one bundled with Confluence)

Resolution

Take a backup of the Confluence Database. Then run this query to remove the wrong plugin:

DELETE FROM PLUGINDATA WHERE PLUGINKEY LIKE '%com.atlassian.confluence.plugins.doctheme%';

After that, shutdown Confluence, remove the plugin caches from the Confluence Home Directory:

• bundled-plugins
• plugins-cache
• plugins-osgi-cache
• plugins-temp

Then startup Confluence