I spent some time trying to resolve this error message when updating solution cell of system coupling block:
System coupling run completed with errors.  Additional information: Exception originated from the noted participant when the coupling service requested ChartableData->GetRootLevelName: Communication socket unexpectedly disconnected.

All that needs to be done to eliminate this error is to change licensing prefs from "Share a single license between applications when possible" to "use a separate license for each application." To check the settings, in Workbench go: Tools>License Preferences... and the GUI will open.

This is mentioned in the System Coupling User's Guide (for v14.0), but they don't say how to check your preferences.