It was a problem with the permissions. To see all plugins and themes that are installed in Wordpress you should use the command:
sudo chown -R www-data:www-data /var/www/domain.com
Can't upload wordpress theme, plugins or images with Filezilla
It was a problem with the permissions. To see all plugins and themes that are installed in Wordpress you should use the command:
sudo chown -R www-data:www-data /var/www/domain.com