What steps will reproduce the problem?
1. Select addons
2. Try to rename them
3.

What is the expected output? What do you see instead?

Its saying this

Date: 2008-11-11 21:19:56
ID: 59
Error occured in: Global
Count: 1
Message: ..\AddOns\ACP\ACP.lua line 436:
   attempt to index a nil value
Debug:
   (tail call): ?
   [C]: ?
   ACP\ACP.lua:436 OnAccept()
   ..\FrameXML\StaticPopup.lua:2792 StaticPopup_OnClick()
   [string "*:OnClick"]:1:
      [string "*:OnClick"]:1
AddOns:
  Swatter, v5.1.3715 (SnaggleTooth)
  ACP, v3.0.3.0.10
  AdvancedTradeSkillWindow, v
  ArkInventory, v3.01
  AtlasLoot, v5.01.04
  AtlasLootFu, v1.2
  Babylonian, v5.1.DEV.130
  Bartender4, v4.1.2
  BeanCounter, v5.1.3715 (SnaggleTooth)
  BonusScanner, v4.1
  Cartographer, v2.0
  CartographerBattlegrounds, v2.0
  CartographerCoordinates, v2.0
  CartographerFoglight, v2.0
  CartographerGroupColors, v2.0
  CartographerGuildPositions, v2.0
  CartographerInstanceLoot, v2.0
  CartographerInstanceMaps, v2.0
  CartographerInstanceNotes, v2.0
  CartographerLookNFeel, v2.0
  CartographerNotes, v2.0
  CartographerPOI, v2.0
  CartographerProfessions, v2.0
  CartographerWaypoints, v2.0
  CartographerZoneInfo, v2.0
  Collectinator, vAlpha 2 r43
  Configator, v5.1.DEV.130
  CooldownTimers3, v3.0 Beta
  CurseProfiler, v
  DebugLib, v5.1.DEV.130
  DrDamage, v1.4.0
  Enchantrix, v5.1.3715 (SnaggleTooth)
  EnchantrixBarker, v5.1.3715 (SnaggleTooth)
  EnhTooltip, v5.1.3715 (SnaggleTooth)
  FuBar, v
  FuBarDurabilityFu, v2.0
  FuBarFriendsFu, v2.4.1-91
  FuBarGuildFu, v2.4.1-98
  FuBarLocationFu, v3.0
  FuBarMoneyFu, vv1.2
  FuBarPerformanceFu, v2.0.0
  FuBarSpeedFu, v2.0.$Revision: 48 $
  FuBarTopScoreFu, v2.0
  GiveMeHealth, v
  HealBot, v3.0.3.0
  Informant, v5.1.3715 (SnaggleTooth)
  InventoryOnPar, v
  LightHeaded, v252
  mbuffbar, v
  Omen, v3.0.2
  OmniCC, v2.2.5
  Outfitter, v4.3b13
  Overachiever, v0.17
  Postal, v3.0.1
  PreformAVEnabler, v
  Quartz, v1.0
  QuartzBuff, v1.0
  QuartzFlight, v1.0
  QuartzFocus, v1.0
  QuartzGCD, v1.0
  QuartzInterrupt, v1.0
  QuartzLatency, v1.0
  QuartzMirror, v1.0
  QuartzPet, v1.0
  QuartzPlayer, v1.0
  QuartzRange, v1.0
  QuartzSwing, v1.0
  QuartzTarget, v1.0
  QuartzTimer, v1.0
  QuartzTradeskill, v1.0
  QuestHelper, v0.66
  RatingBuster, v
  Recount, v
  RedRange, v
  SmartBuff, v3.0b
  SpamEraser, v
  SpartanUI, v2.5.1
  Stubby, v5.1.3715 (SnaggleTooth)
  Talented, v1.9.2
  TalentedData, v1.0
  TradesBar, v2.12.3
  WIM, v3.0.3
  (ck=7c8)

What version of the product are you using?

The latest version on curse

Do you have an error log of what happened?