E2497 Cmd Rej: NI, ZONE, MSA, UN or NPC cannot be C for existing blocked SR

The point code c-c-c, or the npc=c parameter can be specified only for a screening reference that does not alerady exist.

Recovery

1. Display the existing screening references. Enter the rtrv-scr-blkdpc or rtrv-scr-blkopc command.
2. Re-enter the ent-scr-blkdpc or ent-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 Administration - GWS User's Guide for assistance.
   Contact My Oracle Support if this error message appears again. See My Oracle Support (MOS).