You are getting the following error:
System.Remoting.RemotingException: Failed to connect to an IPC Port: The system cannot find the file specified.
It occurs on SMP server.
Workflow 8.6, 8.7
Workflow Server extensions are not installed on SMP server
Do a Silent installation of Workflow Server extensions:
[INSTALLDIR]Web\Agent\
where [INSTALLDIR] is workflow installation folder (Altiris Install Dir + \Altiris\Workflow)