workflow can fail to load when using ParameterSet
A parameter specified in a ParameterSet's config file may be referenced, e.g., in an actor before ParameterSet has loaded the file. When the workflow is loaded, there is a race condition between setting the ParameterSet's file parameter and actor parameters.
I'm attaching a simple example workflow and ParmeterSet config file. (You'll need to change the path to the config file). The workflow sometimes gets an error when it is opened in Kepler.