Hi there,
Just replace this function on theme-options.php file on sampression-lite/includes/theme-options/ directory
function sampression_admin_enqueue_styles() {
/* register */
wp_register_style( 'sampression-theme-options-css', get_template_directory_uri() . '/includes/theme-options/theme-options.css', array(), '1.4', 'screen' );
/* enqueue */
wp_enqueue_style('sampression-theme-options-css');
}
with
function sampression_admin_enqueue_styles() {
/* register */
wp_register_style( 'sampression-theme-options-css', get_template_directory_uri() . '/includes/theme-options/theme-options.css', array(), '1.4', 'screen' );
/* enqueue */
wp_enqueue_style('sampression-theme-options-css');
wp_enqueue_style('thickbox', get_template_directory_uri() . 'wp-includes/js/thickbox/thickbox.css', false, false, 'screen');
}
OR
just add this line
wp_enqueue_style('thickbox', get_template_directory_uri() . 'wp-includes/js/thickbox/thickbox.css', false, false, 'screen');
inside the function
function sampression_admin_enqueue_styles() {
}
Also let me know if this helps.