Pages broken after update
For Drupal 8.3.x you need to update Display Suite as well to 8.3.x (as is stated on the module page: https://www.drupal.org/project/ds). 


  IMPORTANT NOTICE
  
  Due to changes in core a new version is created.
  
  
  Drupal 8.2 or lower: Use Display Suite 8.2
  Drupal 8.3 or higher: Use Display Suite 8.3
  


Maybe that's what causing all your problems; possibly, updating the module will solve your issues.