Below is the error message on the page for Unread Content.
I have the updated version on your systems.
Can you help?

Error: Property access is not allowed yet (0)
#0 /var/www/html/107014/applications/core/modules/front/discover/streams.php(408): IPS\Content\Search\Mysql\_Query->search(NULL, NULL, 1)
#1 /var/www/html/107014/system/Dispatcher/Controller.php(118): IPS\core\modules\front\discover\_streams->manage()
#2 /var/www/html/107014/applications/core/modules/front/discover/streams.php(65): IPS\Dispatcher\_Controller->execute()
#3 /var/www/html/107014/system/Dispatcher/Dispatcher.php(153): IPS\core\modules\front\discover\_streams->execute()
#4 /var/www/html/107014/index.php(13): IPS\_Dispatcher->run()
#5 {main}

Communities on Cloud which are running 4.7 are encountering some intermittent issues. You can follow updates on the status here: Invision Community | Uptime.com

Things should be fine now, so if you are still seeing any issues, please let us know