Laravel debugging help needed

I have a bug on one of our Laravel 5 application and I am trying to solve it. I am a bit new to Laravel but I am willing to learn. I have got the debug log error below but I have difficulties to interpret what Laravel is telling me and how to solve it.

Whoops, looks like something went wrong.
1/1
ErrorException in Pro.php line 376:
Trying to get property of non-object
in Pro.php line 376
at HandleExceptions->handleError('8', 'Trying to get property of non-object', 'home/app/Models/Protocol.php', '376', array('header' => array('size' => '16', 'bold' => true), 'table' => object(Table), 'now' => object(DateTime), 'text' => ' Handicrafts', 'product' => object(Product))) in Pro.php line 376
at Pro->FirstPage() in Pro.php line 294
at Pro->GeneratePro() in Pro.php line 68
at Pro->__construct(object(Booking)) in ProController.php line 67
at ProController->getPro('707')
at call_user_func_array(array(object(ProController), 'getPro'), array('booking_id' => '707')) in compiled.php line 8558
at Controller->callAction('getPro', array('booking_id' => '707')) in compiled.php line 8626
at ControllerDispatcher->call(object(ProController), object(Route), 'getPro') in compiled.php line 8605
at ControllerDispatcher->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in compiled.php line 9244
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in compiled.php line 9227
at Pipeline->then(object(Closure)) in compiled.php line 8606
at ControllerDispatcher->callWithinStack(object(ProController), object(Route), object(Request), 'getProtocol') in compiled.php line 8592
at ControllerDispatcher->dispatch(object(Route), object(Request), 'Controllers\Admin\ProController', 'getPro') in compiled.php line 7583
at Route->runWithCustomDispatcher(object(Request)) in compiled.php line 7554
at Route->run(object(Request)) in compiled.php line 7219
at Router->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in compiled.php line 9244
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in compiled.php line 9227
at Pipeline->then(object(Closure)) in compiled.php line 7220
at Router->runRouteWithinStack(object(Route), object(Request)) in compiled.php line 7209
at Router->dispatchToRoute(object(Request)) in compiled.php line 7194
at Router->dispatch(object(Request)) in compiled.php line 2040
at Kernel->Illuminate\Foundation\Http\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in compiled.php line 9244
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in compiled.php line 2548
at VerifyCsrfToken->handle(object(Request), object(Closure)) in VerifyCsrfToken.php line 17
at VerifyCsrfToken->handle(object(Request), object(Closure)) in compiled.php line 9236
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in compiled.php line 12416
at ShareErrorsFromSession->handle(object(Request), object(Closure)) in compiled.php line 9236
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in compiled.php line 11106
at StartSession->handle(object(Request), object(Closure)) in compiled.php line 9236
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in compiled.php line 12118
at AddQueuedCookiesToResponse->handle(object(Request), object(Closure)) in compiled.php line 9236
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in compiled.php line 12066
at EncryptCookies->handle(object(Request), object(Closure)) in compiled.php line 9236
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in compiled.php line 2589
at CheckForMaintenanceMode->handle(object(Request), object(Closure)) in compiled.php line 9236
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in compiled.php line 9227
at Pipeline->then(object(Closure)) in compiled.php line 1996
at Kernel->sendRequestThroughRouter(object(Request)) in compiled.php line 1983
at Kernel->handle(object(Request)) in index.php line 53

via Chebli Mohamed