500 Internal Server Error

Trying to get property of non-object (8)

#0 /var/www/perantichecontrade.it/public_html/utils/resourcecached.php(138): flight\Engine->handleError(8, 'Trying to get p...', '/var/www/perant...', 138, Array)
#1 /var/www/perantichecontrade.it/public_html/utils/cache.php(82): ResourceCached->{closure}()
#2 /var/www/perantichecontrade.it/public_html/utils/resourcecached.php(149): Cache::make('currentexhibiti...', 14400, Object(Closure))
#3 /var/www/perantichecontrade.it/public_html/index.php(502): ResourceCached->getcurrentexhibition()
#4 /var/www/perantichecontrade.it/public_html/index.php(166): singleColumn(Object(Page), Array)
#5 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(164): {closure}('s', Object(flight\net\Route))
#6 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(143): flight\core\Dispatcher::callFunction(Object(Closure), Array)
#7 /var/www/perantichecontrade.it/public_html/flight/Engine.php(310): flight\core\Dispatcher::execute(Object(Closure), Array)
#8 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(191): flight\Engine->_start()
#9 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(142): flight\core\Dispatcher::invokeMethod(Array, Array)
#10 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(48): flight\core\Dispatcher::execute(Array, Array)
#11 /var/www/perantichecontrade.it/public_html/flight/Engine.php(63): flight\core\Dispatcher->run('start', Array)
#12 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(191): flight\Engine->__call('start', Array)
#13 /var/www/perantichecontrade.it/public_html/flight/core/Dispatcher.php(191): flight\Engine->start()
#14 /var/www/perantichecontrade.it/public_html/flight/Flight.php(43): flight\core\Dispatcher::invokeMethod(Array, Array)
#15 /var/www/perantichecontrade.it/public_html/index.php(528): Flight::__callStatic('start', Array)
#16 /var/www/perantichecontrade.it/public_html/index.php(528): Flight::start()
#17 {main}