The file "/private/var/folders/..." does not exist

I'm trying to upload a jpg file to a public folder by implementing the following codes

private function save_image($request)
    {
        $current_time = Carbon::now('America/Vancouver');
        $year = $current_time->year;
        $month = $current_time->month;
        $day = $current_time->day;
        $hour = $current_time->hour;
        $minute = $current_time->minute;
        $second = $current_time->second;
        $file_extension = $request->file('image_file')->getClientOriginalExtension();

        $new_filename = "product-$year-$month-$day-$hour-$minute-$second".'.'.$file_extension;
        $upload_path = public_path("files/products");
       //error here
        $request->file('image_file')->move($upload_path, $new_filename);
        $request->merge([
            'image' => $upload_path . $new_filename
        ]);
        return $request;
    }

However, the following error page hit me in the face.

=== Whoops, looks like something went wrong.

1/1 FileNotFoundException in File.php line 37: The file "/private/var/folders/_1/bsl_g_650hj2xx3hvyjjz_n40000gn/T/phpc2nB4L" does not exist in File.php line 37 at File->__construct('/private/var/folders/_1/bsl_g_650hj2xx3hvyjjz_n40000gn/T/phpc2nB4L', true) in UploadedFile.php line 96 at UploadedFile->__construct('/private/var/folders/_1/bsl_g_650hj2xx3hvyjjz_n40000gn/T/phpc2nB4L', 'Patern_test.jpg', 'image/jpeg', '36623', '0') in UploadedFile.php line 53 at UploadedFile::createFromBase(object(UploadedFile)) in Request.php line 419 at Request->Illuminate\Http{closure}(object(UploadedFile)) at array_map(object(Closure), array('image_file' => object(UploadedFile))) in Request.php line 420 at Request->convertUploadedFiles(array('image_file' => object(UploadedFile))) in Request.php line 401 at Request->allFiles() in Request.php line 304 at Request->all() in ProductController.php line 68 at ProductController->store(object(ProductCreateRequest), '2') at call_user_func_array(array(object(ProductController), 'store'), array(object(ProductCreateRequest), 'product_group_id' => '2')) in Controller.php line 76 at Controller->callAction('store', array(object(ProductCreateRequest), 'product_group_id' => '2')) in ControllerDispatcher.php line 146 at ControllerDispatcher->call(object(ProductController), object(Route), 'store') in ControllerDispatcher.php line 94 at ControllerDispatcher->Illuminate\Routing{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52 at Pipeline->Illuminate\Routing{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103 at Pipeline->then(object(Closure)) in ControllerDispatcher.php line 96 at ControllerDispatcher->callWithinStack(object(ProductController), object(Route), object(Request), 'store') in ControllerDispatcher.php line 54 at ControllerDispatcher->dispatch(object(Route), object(Request), 'App\Http\Controllers\Dashboard\ProductController', 'store') in Route.php line 174 at Route->runController(object(Request)) in Route.php line 140 at Route->run(object(Request)) in Router.php line 703 at Router->Illuminate\Routing{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52 at Pipeline->Illuminate\Routing{closure}(object(Request)) in VerifyCsrfToken.php line 64 at VerifyCsrfToken->handle(object(Request), object(Closure)) at call_user_func_array(array(object(VerifyCsrfToken), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124 at Pipeline->Illuminate\Pipeline{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32 at Pipeline->Illuminate\Routing{closure}(object(Request)) in ShareErrorsFromSession.php line 49 at ShareErrorsFromSession->handle(object(Request), object(Closure)) at call_user_func_array(array(object(ShareErrorsFromSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124 at Pipeline->Illuminate\Pipeline{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32 at Pipeline->Illuminate\Routing{closure}(object(Request)) in StartSession.php line 62 at StartSession->handle(object(Request), object(Closure)) at call_user_func_array(array(object(StartSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124 at Pipeline->Illuminate\Pipeline{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32 at Pipeline->Illuminate\Routing{closure}(object(Request)) in AddQueuedCookiesToResponse.php line 37 at AddQueuedCookiesToResponse->handle(object(Request), object(Closure)) at call_user_func_array(array(object(AddQueuedCookiesToResponse), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124 at Pipeline->Illuminate\Pipeline{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32 at Pipeline->Illuminate\Routing{closure}(object(Request)) in EncryptCookies.php line 59 at EncryptCookies->handle(object(Request), object(Closure)) at call_user_func_array(array(object(EncryptCookies), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124 at Pipeline->Illuminate\Pipeline{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32 at Pipeline->Illuminate\Routing{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103 at Pipeline->then(object(Closure)) in Router.php line 705 at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 678 at Router->dispatchToRoute(object(Request)) in Router.php line 654 at Router->dispatch(object(Request)) in Kernel.php line 246 at Kernel->Illuminate\Foundation\Http{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52 at Pipeline->Illuminate\Routing{closure}(object(Request)) in CheckForMaintenanceMode.php line 44 at CheckForMaintenanceMode->handle(object(Request), object(Closure)) at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124 at Pipeline->Illuminate\Pipeline{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32 at Pipeline->Illuminate\Routing{closure}(object(Request)) at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103 at Pipeline->then(object(Closure)) in Kernel.php line 132 at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99 at Kernel->handle(object(Request)) in index.php line 54 at require_once('/Users/kimsangmin/Desktop/new_skycadtech.com/public/index.php') in server.php line 21

===

Funny thing is, I have several applications using the same php, mysql, packages(including laravel itself), and same folder permissions and they're working fine! Only this application is causing the issue.

It seems like it's failing to create a temporary jpg file into that /private/var/folders/_1/blahblah folder... I've also tried to delete everything in there but no luck. Has anyone experienced the same issue? What might be the problem here?