cl_equip error

Can somebody tell me what the error is here please? When players open the traitor shop, they crash. Not always, but sometimes.

[ERROR] gamemodes/terrortown/gamemode/cl_equip.lua:204: attempt to call method ‘IsEquipment’ (a nil value)

  1. unknown - gamemodes/terrortown/gamemode/cl_equip.lua:204
  2. unknown - lua/includes/modules/concommand.lua:69

cl_equip - http://pastebin.com/zwgNKZ0M

Addons:

BiohazardBall
Bombstation
Defibrillator
Detective Camera
Easy Adverts
fc_vote
Grapplehook
Mail
Chat tags
MelonMine
Ban message
Phone Bomb
Pointshop (undefined)
Shoutmenu
Shuriken
Sleek loadout
Steamgroup rewards
Stungun
Traitor Sentry
Tripmine
Turtle grenade
TTT Chicken
voicechatmeter
Auto Director by Hobbes
Server hopper by Hobbes
Media player by Hobbes
Tag editor by Hobbes
Events by Hobbes
Blackhold grenade by Hobbes

It means you are trying to use a function that doesn’t exist or exists but in other realm than clientside/serverside.