Message Oracle NNL-00016 - cannot start server, error getting program directorys name

ERRORcannot start server, error getting program directorys name
CAUSEThe user issued a STARTUP request, but the control program was unable to start the server because it was unable to find the name of the directory where the server executable resides.
ACTIONAn internal error not normally visible to the user. Contact Worldwide Customer Support.