This post should fix the issue found here: https://www.emucoach.com/showthread.php/5644-v10-Silvermoon-Inscription-Trainer-and-Vendor-Faction
Code:
UPDATE `creature_template` SET `faction_A`='1604', `faction_H`='1604' WHERE `entry`=30710;
UPDATE `creature_template` SET `faction_A`='1604', `faction_H`='1604' WHERE `entry`=30727;