function bp_core_activation_notice() {
	global $wp_rewrite, $wpdb;

	// Only the super admin gets warnings.
	if ( ! bp_current_user_can( 'bp_moderate' ) ) {
		return;
	}

	// Bail in user admin.
	if ( is_user_admin() ) {
		return;
	}

	// On multisite installs, don't load on a non-root blog, unless do_network_admin is overridden.
	if ( is_multisite() && bp_core_do_network_admin() && ! bp_is_root_blog() ) {
		return;
	}

	// Bail if in network admin, and BuddyPress is not network activated.
	if ( is_network_admin() && ! bp_is_network_activated() ) {
		return;
	}

	/**
	 * Check to make sure that the blog setup routine has run. This can't
	 * happen during the wizard because of the order which the components
	 * are loaded.
	 */
	if ( bp_is_active( 'blogs' ) ) {
		$bp    = buddypress();
		$count = $wpdb->get_var( "SELECT COUNT(*) FROM {$bp->blogs->table_name}" );

		if ( empty( $count ) ) {
			bp_blogs_record_existing_blogs();
		}
	}

	// Add notice if no rewrite rules are enabled.
	if ( empty( $wp_rewrite->permalink_structure ) ) {
		bp_core_add_admin_notice( sprintf( __( '<strong>BuddyPress is almost ready</strong>. You must <a href="%s">update your permalink structure</a> to something other than the default for it to work.', 'buddypress' ), admin_url( 'options-permalink.php' ) ), 'error' );
	}

	// Get BuddyPress instance.
	$bp = buddypress();

	/**
	 * Check for orphaned BP components (BP component is enabled, no WP page exists).
	 */
	$orphaned_components = array();
	$wp_page_components  = array();

	// Only components with 'has_directory' require a WP page to function.
	foreach( array_keys( $bp->loaded_components ) as $component_id ) {
		if ( !empty( $bp->{$component_id}->has_directory ) ) {
			$wp_page_components[] = array(
				'id'   => $component_id,
				'name' => isset( $bp->{$component_id}->name ) ? $bp->{$component_id}->name : ucwords( $bp->{$component_id}->id )
			);
		}
	}

	// Activate and Register are special cases. They are not components but they need WP pages.
	// If user registration is disabled, we can skip this step.
	if ( bp_get_signup_allowed() ) {
		$wp_page_components[] = array(
			'id'   => 'activate',
			'name' => __( 'Activate', 'buddypress' )
		);

		$wp_page_components[] = array(
			'id'   => 'register',
			'name' => __( 'Register', 'buddypress' )
		);
	}

	// On the first admin screen after a new installation, this isn't set, so grab it to suppress
	// a misleading error message.
	if ( empty( $bp->pages->members ) ) {
		$bp->pages = bp_core_get_directory_pages();
	}

	foreach( $wp_page_components as $component ) {
		if ( !isset( $bp->pages->{$component['id']} ) ) {
			$orphaned_components[] = $component['name'];
		}
	}

	if ( !empty( $orphaned_components ) ) {
		$admin_url = bp_get_admin_url( add_query_arg( array( 'page' => 'bp-page-settings' ), 'admin.php' ) );
		$notice    = sprintf(
			'%1$s <a href="%2$s">%3$s</a>',
			sprintf(
				__( 'The following active BuddyPress Components do not have associated WordPress Pages: %s.', 'buddypress' ),
				'<strong>' . implode( '</strong>, <strong>', array_map( 'esc_html', $orphaned_components ) ) . '</strong>'
			),
			esc_url( $admin_url ),
			__( 'Repair', 'buddypress' )
		);

		bp_core_add_admin_notice( $notice );
	}

	// BP components cannot share a single WP page. Check for duplicate assignments, and post a message if found.
	$dupe_names = array();
	$page_ids   = bp_core_get_directory_page_ids();
	$dupes      = array_diff_assoc( $page_ids, array_unique( $page_ids ) );

	if ( !empty( $dupes ) ) {
		foreach( array_keys( $dupes ) as $dupe_component ) {
			$dupe_names[] = $bp->pages->{$dupe_component}->title;
		}

		// Make sure that there are no duplicate duplicates :).
		$dupe_names = array_unique( $dupe_names );
	}

	// If there are duplicates, post a message about them.
	if ( !empty( $dupe_names ) ) {
		$admin_url = bp_get_admin_url( add_query_arg( array( 'page' => 'bp-page-settings' ), 'admin.php' ) );
		$notice    = sprintf(
			'%1$s <a href="%2$s">%3$s</a>',
			sprintf(
				__( 'Each BuddyPress Component needs its own WordPress page. The following WordPress Pages have more than one component associated with them: %s.', 'buddypress' ),
				'<strong>' . implode( '</strong>, <strong>', array_map( 'esc_html', $dupe_names ) ) . '</strong>'
			),
			esc_url( $admin_url ),
			__( 'Repair', 'buddypress' )
		);

		bp_core_add_admin_notice( $notice );
	}
}