- laravel framework upgrade frpm 7.x to 8. see also: https://laravel.com/docs/8.x/upgrade#assert-exact-json-method

- use  PHP7 null coalesce operator instead of laravel optional method
- change Breadcrumbs::register method to Bredcrumbs::for method
- composer updates

app/Models/Title.php

@@ -3,9 +3,11 @@ namespace App\Models;
 
 use Illuminate\Database\Eloquent\Model;
 use App\Models\Dataset;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
 
 class Title extends Model
 {
+    use HasFactory;
     protected $table = 'dataset_titles';
     public $timestamps = false;