Laravel-datatables: le filtre des tables de données ne fonctionne pas

donc j'utilise laravel 5.4 et j'utilise datatables ajax avec mon éloquent est avoir une table de jointure et ainsi de suite, maintenant je veux faire une recherche/filtre ça ne fonctionne tout simplement pas, j'ai eu une erreur de serveur interne 500 une idée pourquoi?

voici mon code contrôleur`

public function index()
    {
        try{
            return view('admins.'.$this->kelaspath.'.index');
        }catch (Exception $e){
            return Redirect::back()->withInput()->with('errormessage',$e->getMessage());
        }
    }

    public function data_kegiatan()
    {
        $data = Kegiatan::with('tempat','sasaranhub.sasaran','prasyarat.kegiatan','total_peserta');
        $datatable = Datatables::of($data)
        ->editColumn('kota', function($data){
            return $data->tempat ? $data->tempat->kota : $data->kota;
        })
        ->editColumn('tempat', function($data){
            return $data->tempat ? $data->tempat->name : '';
        })
        ->editColumn('tanggal', function($data){
            return $data->tanggal ? with(new Date($data->tanggal))->format('d F Y') : '';
        })
        ->editColumn('tanggal2', function($data){
            return $data->tanggal2 ? with(new Date($data->tanggal2))->format('d F Y') : '';
        })
        ->editColumn('status', function($data){
            if($data->status == 1){
                $status = '<a class="btn btn-default btn-sm nopointer"><i class="fa fa-pause"></i> <span class="hidden-xs">MENUNGGU</span></a>';
            }elseif($data->status == 2){
                $status = '<a class="btn btn-warning btn-sm nopointer"><i class="fa fa-circle-o"></i> <span class="hidden-xs">PENDAFTARAN TERBUKA</span></a>';
            }elseif($data->status == 3){
                $status = '<a class="btn btn-warning btn-sm disabled"><i class="fa fa-ban"></i> <span class="hidden-xs">PENDAFTARAN TERTUTUP</span></a>';
            }elseif($data->status == 4){
                $status = '<a class="btn btn-primary btn-sm disabled"><i class="fa fa-dot-circle-o"></i> <span class="hidden-xs">BERJALAN</span></a>';
            }elseif($data->status == 5){
                $status = '<a class="btn btn-primary btn-sm nopointer"><i class="fa fa-times"></i> <span class="hidden-xs">TERLAKSANA</span></a>';
            }elseif($data->status == 6){
                $status = '<a class="btn btn-danger btn-sm nopointer"><i class="fa fa-times"></i> <span class="hidden-xs">BATAL</span></a>';
            }else{
                $status = "-";
            }
            return $status;
        })
        ->editColumn('sasaranhub', function($data){
            $sasaran = '';
            if(!empty($data->sasaranhub)){
                foreach ($data->sasaranhub as $sr) {
                    $sasaran .= '<a class="btn btn-info btn-xs nopointer marginbottom" >' . $sr->sasaran->name . '</a> ';
                }
            }
            return $sasaran;
        })
        ->editColumn('prasyarat', function($data){
            $prasyarat = '';
            if(!empty($data->prasyarat)){
                foreach ($data->prasyarat as $pr) {
                    $prasyarat .= '<a class="btn btn-info btn-xs nopointer marginbottom">' . $pr->kegiatan->kode . ' - ' . $pr->kegiatan->name . '</a> ';
                }
            }
            return $prasyarat;
        })
        ->addColumn('durasi',function($data){
            $mulai = new \Carbon\Carbon($data->tanggal);
            $startTimeStamp = strtotime($mulai->subDays(1));
            $endTimeStamp = strtotime($data->tanggal2);
            $timeDiff = abs($endTimeStamp - $startTimeStamp);
            $numberDays = $timeDiff/86400;
            $numberDays = intval($numberDays);

            return $numberDays;
        })
        ->rawColumns(['sasaranhub', 'prasyarat','status'])->make(true);


        return $datatable;   
    }

et voici ma datatable jquery

var table = $('#dataTables-example').DataTable({
        dom: '<"top"B>t<"bottom"p>',
        processing: true,
        serverSide: true,
        ajax: '{!! route('admins.kegiatan.data_kegiatan') !!}',
        responsive:{
            details:{
                type: 'column',
                target: -1
            }
        },
        columns: [
            { data: 'id', name: 'kegiatan.id', visible : false, searchable : false },
            { data: 'status', name: 'kegiatan.status',visible : false, searchable : false  },
            { data: 'name', name: 'kegiatan.name', className: 'warptext'},
            { data: 'kota', name: 'kegiatan.kota'},
            { data: 'tempat', name: 'kegiatan.tempat',className: 'warptext'},
            { data: 'tanggal', name: 'kegiatan.tanggal'},
            { data: 'tanggal2', name: 'kegiatan.tanggal2' },
            { data: 'durasi', name: 'durasi', render: function(data){
                return data ? data + ' hari' : '-';
            }},

            { data: 'status', name: 'kegiatan.status'},
            { data: 'sasaranhub', name: 'kegiatan.sasaranhub' },
            { data: 'prasyarat', name: 'kegiatan.prasyarat', render:function(data){
                return data ? data : '-';
            } },

            { data: 'min', name: 'kegiatan.min' },
            { data: 'max', name: 'kegiatan.maks' },
            { data: 'max', name: 'kegiatan.terdaftar'},
            { data: null, orderable: 'false', searchable: 'false', className:'control', defaultContent: ''}
        ],
        buttons: [
            {
                extend:'colvis',
                columns: ':gt(1)',
                text: '<i class="fa fa-table"></i>'
            },
            {
                extend:'colvisGroup',
                text: 'Semua',
                hide: [0,1],
                show: ':hidden'
            }
        ],
        language: {
            buttons : {},
            select:{
                rows:{
                    _: "",
                    0: "",
                    1: ""
                }
            },
            "sProcessing":   "Sedang proses...",
            "sLengthMenu":   "Tampilan _MENU_ entri",
            "sZeroRecords":  "Tidak ditemukan data yang sesuai",
            "sInfo":         "Tampilan _START_ sampai _END_ dari _TOTAL_ entri",
            "sInfoEmpty":    "Tampilan 0 hingga 0 dari 0 entri",
            "sInfoFiltered": "(disaring dari _MAX_ entri keseluruhan)",
            "sInfoPostFix":  "",
        }
    });
    $('#searchtext').keyup(function(){
        table.search($(this).val()).draw() ;
    });

et voici aussi mon tableau html

<div class="input-group tabletools">
    <div class="input-group-addon"><i class="fa fa-search"></i></div>
    <input type="text" id="searchtext" class="form-control" placeholder="Kata kunci pencarian...">
</div>
<table class="table table-hover" id="dataTables-example" cellspacing="0" width="100%">
    <thead class="bg-light-blue-active color-palette">
    <tr>
        <th hidden>id</th>
        <th hidden>status</th>
        <th data-priority="1">Nama </th>
        <th>Kota</th>
        <th>Tempat</th>
        <th class="sort" data-priority="4">Mulai</th>
        <th data-priority="3">Selesai</th>
        <th>Durasi</th>
        <th data-priority="2">Status</th>
        <th class="none">Sasaran</th>
        <th class="none">Prasyarat</th>
        <th class="none">Min</th>
        <th class="none">Maks</th>
        <th class="none">Terdaftar</th>
        <th></th>
    </tr>
    </thead>
</table>