During the configuration dialog (i.e. adding a configuration a CLM to a Windchill artifact) phase, you'll get to
a point where you'll have to select the configuration link to the windchill artifact. At that point, you may get an error with a red message:
Unable to request the Configuration Dialog.
When this error happens, you've to remake your
friending (i.e. linking a CLM project area to OSLC Connect for Windchill) with the GC application.