Symptoms

Menu titles and menu items appear broken in Confluence Admin and/or Space Admin:

$section.label.getDisplayableLabel($req, $action.webInterfaceContext)

Cause

One or more plugins are incompatible with the Confluence version

Resolution

Please upgrade all of your existing plugins and uninstall all plugins that have no compatible versions.

If a plugin cannot be uninstalled, please proceed to delete the plugin manually through the database as explained here: Removing Malfunctioning Plugins