Error "The computer is running on unspported operating system and cannot be registered as Task Server." is present log files.
Task Servers will not register clients
Task Server will not bind to ports The computer is running on unspported operating system and cannot be registered as Task Server.
This is due to the client task server having an older version of client task server and they are attempting to register as a task server. The client itself is a unsupported OS for the new client task server version.
Please review the release notes for the SMP version that you are on to see what operating systems are supported as task servers.
Client Task services will need to be removed from unsupported OSs and moved to a client with a supported OS.