save-current-session closes all windows and stops multiprocessing, saves an image at the location supplied in pathname, and restarts multiprocessing and the windows. For more information see Saved sessions.
save-current-sessionis intended for saving the state of a windowing image. While
save-current-sessioncan be used to save a session in a console image, this achieves nothing more than save-image.
save-current-session, starting the supplied image (for example via the Windows start menu or MAc OS X Dock) will run itself only if the default session is "LispWorks Release".
LispWorks User Guide and Reference Manual - 20 Sep 2017