The 2022-05 .NET Cumulative Update (KB5013868) released by Microsoft in May, 2022 has been reported to cause communication issues between Brightsign players and Carousel 7.
When the update is applied, Brightsign players may not respond to channel changes or power save commands and channel content may stop updating.
If the update has been applied to a Carousel 7 Server and brightsign players are in this state, simply reboot the players to restore proper connectivity. Either physically power cycling the players (manually unplugging, using a managed POE network switch etc) or rebooting through the players DWS console will work.
If you want to use DWS to reboot remotely, ensure it's enabled before the .NET updates (since communication won't work through Carousel). Here are the instructions for that:
Log in to the Carousel 7 UI and navigate to the player dashboard. Select the player, note its IP address and edit its settings. Under Brightsign Settings, enable Diagnostic Web Server and set a password. Then save and exit the settings page, allowing the player to reboot and apply the DWS setting.
Once it has rebooted, you'll be able to access the BrightSign interface via HTTP://<IPADDRESS:PORT>