Platform:
Win 7 64bit

ISP:
VM

Type of Internet Connection:
Fibre Optic

Internet Connection Speed:
150mbps

Date & Time:
20:37PM BST (but anytime)

Frequency:
Always

Character Name:
Sirmarki

Race:
Hume M

World:
Asura

Main Job:
WAR

Support Job:
SAM

Area and Coordinates:
Port Jeuno (M) Homepoint (but any city)

Party or Solo:
Solo

NPC Name:
N/A

Monster Name:
N/A

Steps:
Try to add players to the blacklist, using the following command
/blist add <name>

Does not add player, and results in error "Failed to add to Blacklist".