If that is the case, try renaming the quest file so that it doesn't load. If that corrects the problem, the only part of the quest I think may cause a problem is this part:
Code:
if($class eq 'Warrior'){quest::summonitem(1569);}
elsif($class eq 'Cleric'){quest::summonitem(1582);}
elsif($class eq 'Paladin'){quest::summonitem(1577);}
elsif($class eq 'Ranger'){quest::summonitem(1569);}
elsif($class eq 'Shadowknight'){quest::summonitem(1577);}
elsif($class eq 'Druid'){quest::summonitem(1582);}
elsif($class eq 'Monk'){quest::summonitem(1579);}
elsif($class eq 'Bard'){quest::summonitem(1569);}
elsif($class eq 'Rogue'){quest::summonitem(1581);}
elsif($class eq 'Shaman'){quest::summonitem(1582);}
elsif($class eq 'Necromancer'){quest::summonitem(1581);}
elsif($class eq 'Wizard'){quest::summonitem(1581);}
elsif($class eq 'Magician'){quest::summonitem(1581);}
elsif($class eq 'Enchanter'){quest::summonitem(1581);}
elsif($class eq 'Beastlord'){quest::summonitem(1579);}
elsif($class eq 'Berserker'){quest::summonitem(1577);}
Try removing that part from the quest and try using the quest again and see what happens. You can also turn more logging on by editing the log.ini file so you can see more info to help you catch the cause of the problem.