E2496 Cmd Rej: NI, ZONE, MSA, UN or NPC cannot be C - more than one exists

The point code c-c-c, or npc=c, cannot be deleted until all other entries in the screening reference have been deleted.

Recovery

1. Display the entries in the screening reference. Enter the rtrv-scr-blkdpc or rtrv-scr-blkopc command.
2. Re-enter the dlt-scr-blkdpc or dlt-scr-blkopc command that generated this error message, specifying a valid combination of parameters. Refer to the command description in Commands User's Guide and to the Database Admnistration - GWS User's Guide for assistance.
   Contact My Oracle Support if this error message appears again. See My Oracle Support (MOS).