erro ao deletar edital

app/Evento.php

@@ -3,9 +3,11 @@
 namespace App;
 
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\SoftDeletes;
 
 class Evento extends Model
 {
+  use SoftDeletes;
   /**
    * The attributes that are mass assignable.
    *

database/migrations/2020_02_05_123153_create_eventos_table.php

@@ -36,6 +36,7 @@ class CreateEventosTable extends Migration
             $table->string('pdfEdital')->nullable();
             $table->string('modeloDocumento')->nullable();
             $table->string('anexosStatus')->nullable();
+            $table->softDeletes();
             
         });
     }