Upgrade to Drupal 9 from8 having Twig related error

Question

I recently upgrade drupal to 9 versions via composer. And i am getting following error in drush watchdog:show command

Error: Class 'Twig_Function_Function' not found in  
Drupal\bookmark_field\TwigExtension\BookmarkExtension->getFunctions()

Answer 1

Twig_Function_Function is a deprecated class from Twig 1, the use of which was deprecated in Drupal 8 and has now been removed as Drupal 9 requires Twig 2.

In your bookmark_field module, you need to update the code to use \Twig\TwigFunction instead of the old Twig_Function_Function.