Tabs within Page tabs

I have page tabs within a settings page. On one of these tab pages I have section tabs. On this page I get the following error. I’m not sure what is wrong with my code to cause this issue?

Notice: Undefined index: tab_slug in […]/admin/apf/factory/admin_page/AdminPageFramework.php on line 339

Plugin Page:

// -- Function Name : setUp
		// -- Params : 
		// -- Purpose : Sets up the page and tabs
		function setUp(){
			$this->setRootMenuPageBySlug('edit.php?post_type=dat_cpt');
			$this->addSubMenuItem(array('title' => 'Settings','page_slug' => 'dat_settings'));
			$this->setPageHeadingTabsVisibility(false);
			// disables the page heading tabs by passing false.
			$this->setInPageTabTag('h2');
			// sets the tag used for in-page tabs
			// Add form sections
			$this->addInPageTabs('dat_settings', // set the target page slug so that the 'page_slug' key can be omitted from the next continuing in-page tab arrays.
			array('tab_slug' => 'dat_email_settings', // avoid hyphen(dash), dots, and white spaces
				'title' => __('Email Notification Settings', 'dat-email-notification-settings') ,),

			array('tab_slug' => 'dat_custom_template', // avoid hyphen(dash), dots, and white spaces
				'title' => __('Custom Template', 'dat-custom-template') ,),

			array('tab_slug' => 'dat_form_settings', // avoid hyphen(dash), dots, and white spaces
				'title' => __('Form Settings', 'dat-form-settings') ,),

			array('tab_slug' => 'dat_support',
				'title' => __('Support', 'dat-support'),));
			
		}

Plugin Page Tab Content:

// -- Function Name : load_dat_settings_dat_form_settings
		// -- Params : $oAdminPage
		// -- Purpose : Loads all fields for the form settings page
		function load_dat_settings_dat_form_settings($oAdminPage){

			$this->addSettingSections(
   				array(
    				'section_id'        => 'dat_form_settings_name_section',
    				'section_tab_slug'  => 'form_settings_tabbed',
    				'title'             => 'Name Field',
    				
				),
				array(
    				'section_id'        => 'dat_form_settings_job_title_section',
    				'section_tab_slug'  => 'form_settings_tabbed',
    				'title'             => 'Job Title Field',
				),
				array(
    				'section_id'        => 'dat_form_settings_company_name_section',
    				'section_tab_slug'  => 'form_settings_tabbed',
    				'title'             => 'Company Name Field',
				),
				array(
    				'section_id'        => 'dat_form_settings_photo_section',
    				'section_tab_slug'  => 'form_settings_tabbed',
    				'title'             => 'Photo Field',
				),
				array(
    				'section_id'        => 'dat_form_settings_testimonial_section',
    				'section_tab_slug'  => 'form_settings_tabbed',
    				'title'             => 'Testimonial Field',
				)
			);

			$this->addSettingFields(
    'dat_form_settings_name_section', // the target section ID
    array(
    'field_id'      => 'dat_form_settings_name_enabled',
    'title'         => __( 'Hide Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will hide the "Name" field of the testimonial form. Note this is the "post title" so all testimonials will be untitled',
    'default'   => false,
),
    array(
    'field_id'      => 'dat_form_settings_name_required',
    'title'         => __( 'Not a Required Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will make the "Name" field no longer required.',
    'default'   => false,
),
    array(
   'field_id'          => 'dat_form_settings_name_label',
    'title'             => __( 'Label', 'admin-page-framework-loader' ),
    'type'              => 'text',
    'default'           => 'Name',
),
    'dat_form_settings_job_title_section', // the target section ID
    array(
    'field_id'      => 'dat_form_settings_job_title_enabled',
    'title'         => __( 'Hide Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will hide the "Name" field of the testimonial form. Note this is the "post title" so all testimonials will be untitled',
    'default'   => false,
),
    array(
    'field_id'      => 'dat_form_settings_job_title_required',
    'title'         => __( 'Not a Required Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will make the "Name" field no longer required.',
    'default'   => false,
),
    array(
   'field_id'          => 'dat_form_settings_job_title_label',
    'title'             => __( 'Label', 'admin-page-framework-loader' ),
    'type'              => 'text',
    'default'           => 'Job Title',
),
    'dat_form_settings_company_name_section', // the target section ID
    array(
    'field_id'      => 'dat_form_settings_company_name_enabled',
    'title'         => __( 'Hide Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will hide the "Name" field of the testimonial form. Note this is the "post title" so all testimonials will be untitled',
    'default'   => false,
),
    array(
    'field_id'      => 'dat_form_settings_company_name_required',
    'title'         => __( 'Not a Required Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will make the "Name" field no longer required.',
    'default'   => false,
),
    array(
   'field_id'          => 'dat_form_settings_company_name_label',
    'title'             => __( 'Label', 'admin-page-framework-loader' ),
    'type'              => 'text',
    'default'           => 'Company Name',
),
     'dat_form_settings_photo_section', // the target section ID
    array(
    'field_id'      => 'dat_form_settings_photo_enabled',
    'title'         => __( 'Hide Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will hide the "Name" field of the testimonial form. Note this is the "post title" so all testimonials will be untitled',
    'default'   => false,
),
    array(
    'field_id'      => 'dat_form_settings_photo_required',
    'title'         => __( 'Not a Required Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will make the "Name" field no longer required.',
    'default'   => false,
),
    array(
   'field_id'          => 'dat_form_settings_photo_label',
    'title'             => __( 'Label', 'admin-page-framework-loader' ),
    'type'              => 'text',
    'default'           => 'Photo',
),
    'dat_form_settings_testimonial_section', // the target section ID
    array(
    'field_id'      => 'dat_form_settings_testimonial_enabled',
    'title'         => __( 'Hide Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will hide the "Name" field of the testimonial form. Note this is the "post title" so all testimonials will be untitled',
    'default'   => false,
),
    array(
    'field_id'      => 'dat_form_settings_testimonial_required',
    'title'         => __( 'Not a Required Field', 'admin-page-framework-loader' ),
    'type'          => 'checkbox',
    'description' => 'This will make the "Name" field no longer required.',
    'default'   => false,
),
    array(
   'field_id'          => 'dat_form_settings_testimonial_label',
    'title'             => __( 'Label', 'admin-page-framework-loader' ),
    'type'              => 'text',
    'default'           => 'Photo',
),
     array(
   'field_id'          => 'dat_form_settings_testimonial_limit',
    'title'             => __( 'Character Limit', 'admin-page-framework-loader' ),
    'type'              => 'text',
    'default'           => '',
)
);

		}