Install SluggableModel.php problem

[greenlevel]

I am trying to install this cms but i get the following error when I am with the following step
$ php artisan db:seed after Seeding: CategoriesTableSeeder

In SluggableModel.php line 38:

Type error: Argument 1 passed to App\Base\SluggableModel::customizeSlugEngi
ne() must be an instance of App\Base\Slugify, instance of Cocur\Slugify\Slu
gify given, called in /home/vagrant/code/oz/vendor/cviebrock/eloquent-slugg
able/src/Services/SlugService.php on line 199

Please advice. Thank you

[ozdemirburak]

Sorry, that's my bad, please add the line below after the namespace declaration.

use Cocur\Slugify\Slugify;