I have a problem with a workflow plugin ? (closed) [closed]

I caught this error when I used a workflow plugin.

Error: Class 'Drupal\feeds\Plugin\Derivative\ExtraLinks' not found in include() (line 10 of /usr/www/users/annalind/modules/contrib/feeds_tamper/src/Plugin/Derivative/ExtraLinks.php)

I can't fix the error. I have already installed the Workflow module 8.x-1.7 and the Feeds module 8.x-3.0-alpha11 (or 8.x-2.0-beta3).