Administration menu not visible or 'Admin Menu Section' plugin disabled
Problem
The 'Administration' menu is not showing. Instead, only a 'Hide All' link is visible.
Cause
The 'Admin Menu Section' plugin was disabled. At this time Atlassian is unsure of a root cause. We have seen this occur infrequently after upgrades or LDAP configuration changes.
Workaround
The plugin can be re-enabled by visiting it's URL directly:
http://<baseurl>/secure/admin/jira/ViewPlugins.jspa?mode=enable&pluginKey=jira.webfragments.admin
This should re-enable the plugin and display the 'Admin Menu Section'.
Resolution
The ability to disable this plugin has been removed. The workaround can correct any lingering invalid state.