php - Laravel fill returns null -

i want update product in laravel, not work properly,

my controller's update method looks this:

public function updateproduct(request $request) {     # input values     $data = $request->all();     $productid = $data['id'];     $product = product::find($productid);      $product->fill($data);     # validate  input     $validator = validator::make($request->all(), product::$rules);      if ($product->save())     {         # save language selection         $lscounter = 0;         $langselecname = $request->input('language');         $langselecfile = $request->file('language');          if ($langselecname)         {             $projectpath = $dprojectpath . "languages";              foreach ($langselecname $langselecnamekey => $langselecnamevalue)             {                 if ($langselecfile[$lscounter]['input_vid_lang'] != null)                 {                     $langvidfilename = $langselecfile[$lscounter]['input_vid_lang']->getclientoriginalname();                      $languages = new language();                     $languages['short_name'] = $langselecnamevalue;                     $languages['input_video'] = $projectlangpath . '\\' . $langvidfilename;                      $languages->product()->associate($product);                      $langdata = [                         'languagesshortname' => $languages['short_name'],                         'languagesinputvideo' => $languages['input_video']                     ];                      $intproductid = intval($productid);                     $findlangid = $languages->find($intproductid);                      $findlangid->fill($langdata);                      if ($languages->save())                     {                         $langselecfile[$lscounter]['input_vid_lang']->move($projectlangpath, $langvidfilename);                     }                 }                  $lscounter++;             }         }      } else {         return redirect()->route('editproduct', $productid)->with('message', 'error')->withinput();     } 

i following error after try update it, error looks this:

call member function fill() on null

and points line:

$findlangid->fill($langdata); 

i appreciate help, thank you.

edit

ok people said $intproductromid null, correct product id if dd($intproductromid).

as per comments, following line return null:

$findlangid = $languages->find($intproductromid); 

meaning won't valid:

$findlangid->fill($langdata); 

in other words, if var_dump out $languages->all(), not find $intproductromid in there. if unsure, swap out ->find ->findorfail() (which, considering aren't doing error catching or checking, should using instead).

edit

after conversation in comments, has been established wrong field being used reference. use where instead:

$languages->where('product_rom_id', $intproductromid);