laravel - unserialize error from a column in database -

since 1 day have exception view when want access unserialized column. it's strange because in pages it's working , others error

hope me .. don't know why work , not. tested base64_encode() , base64_decode() error views different records

unserialize error offet

here controller when create new order

     $order = new order();      $order->cart = serialize($cart);      ...      $order->save(); 

now controller when unserialize

public function show($id)   {       $order = order::findorfail($id);       $order->cart = unserialize($order->cart);       $order->cart->totalprice;       $prix_total = $order->cart->totalprice;       $structure_id = $order->structure_id;       $structure = structure::where('id' , '=' , $structure_id)->first();       $federation = structure::where('id' , '1')->first();        return view('cotisation_structure/show' , compact('prix_total', 'order' , 'structure' , 'federation'));    } 

now view display records in "cart" column :

@foreach($order->cart->items $item)                        <tr>                            @if(auth::user()->isfederation())                                <td><input type="checkbox" name="checkbox[]" value="{{$item['item']->id}}"></td>                            @endif                            <td><a href="{!! route('licencie.show', $item['item']->id) !!}">{{$item['item']->num_licence}}</a></td>                            <th>{{$item['item']->lb_nom}}</th>                            <th>{{$item['item']->lb_prenom}}</th>                            <th>{{$item['item']->structure->nom_structure}}</th>                                <td>                                    @if($item['item']->lb_tricolore != null)                                        {{$item['item']->lb_activite_tricolore}} - {{$item['item']->lb_tricolore}}                                    @else                                        {{$item['item']->activite_licencie->lb_activite}}                                    @endif                                </td>                            <th>{{$item['item']->saison->lb_saison}}</th>                            <th>{{$order->payment_method}}</th>                            <th>{{$item['price']}} € </th>                            <td>{{carbon\carbon::parse($order->date_achat)->format('d/m/y')}}</td>                        </tr>                     @endforeach 

it possible storing serialized field in string type of database table field , gets stripped @ 255 characters.

for further debugging recommend save serialized data log , when restoring also. in case can compare if data saved same taken out.