Add this code in your active theme's functions.php file to disable default jquery on pdfviewer pages.

deregister-jquery-on-single-post-type-worpress.php

add_action( 'wp_enqueue_scripts', 'themencode_control_jquery' ); 
function themencode_control_jquery(){
  if( is_singular() && get_post_type()=='pdfviewer' ){
    wp_deregister_script('jquery');
  }
}