Just rolled a new Human Monk, and after the cut scene at Northshire, the following error popped up:

Date: 2015-01-18 12:20:41
ID: 1
Error occured in: Global
Count: 1
Message: ..\AddOns\WoWPro\WoWPro_Mapping.lua line 408:
attempt to compare number with nil
Debug:
WoWPro\WoWPro_Mapping.lua:408:
WoWPro\WoWPro_Mapping.lua:405
(tail call): ?
WoWPro\WoWPro_Mapping.lua:604: MapPoint()
WoWPro\WoWPro_Events.lua:201: AutoCompleteQuestUpdate()
WoWPro\WoWPro_Parser.lua:460:
WoWPro\WoWPro_Parser.lua:398
(tail call): ?

[string "safecall Dispatcher[1]"]:9:
[string "safecall Dispatcher[1]"]:5
(tail call): ?
...nterface\AddOns\Ace3\AceBucket-3.0\AceBucket-3.0.lua:118: func()
Ace3\AceTimer-3.0\AceTimer-3.0.lua:55:
Ace3\AceTimer-3.0\AceTimer-3.0.lua:48
Locals:
None
AddOns:
BlizzBugsSuck, v6.0.3.2
Swatter, v5.21c.5521 (SanctimoniousSwamprat)
Accountant, v6.01.60000
Ace3, v
ACP, v3.4.14
Arh, v1.4.2
AskMrRobot, v19
AucAdvanced, v5.21c.5521 (SanctimoniousSwamprat)
AucFilterBasic, v5.21c.5521 (SanctimoniousSwamprat)
AucFilterOutlier, v5.21c.5521.5459(5.21c/embedded)
AucMatchUndercut, v5.21c.5521.5507(5.21c/embedded)
AucStatHistogram, v5.21c.5521 (SanctimoniousSwamprat)
AucStatiLevel, v5.21c.5521 (SanctimoniousSwamprat)
AucStatPurchased, v5.21c.5521 (SanctimoniousSwamprat)
AucStatSales, v5.21c.5521.5476(5.21c/embedded)
AucStatSimple, v5.21c.5521 (SanctimoniousSwamprat)
AucStatStdDev, v5.21c.5521 (SanctimoniousSwamprat)
AucStatWOWEcon, v5.21c.5521.5323(5.21c/embedded)
AucUtilAHWindowControl, v5.21c.5521.5347(5.21c/embedded)
AucUtilAppraiser, v5.21c.5521.5495(5.21c/embedded)
AucUtilAskPrice, v5.21c.5521.5447(5.21c/embedded)
AucUtilAutoMagic, v5.21c.5521.5443(5.21c/embedded)
AucUtilCompactUI, v5.21c.5521.5496(5.21c/embedded)
AucUtilEasyBuyout, v5.21c.5521.5507(5.21c/embedded)
AucUtilFixAH, v5.21c.5521 (SanctimoniousSwamprat)
AucUtilItemSuggest, v5.21c.5521.5417(5.21c/embedded)
AucUtilPriceLevel, v5.21c.5521.5458(5.21c/embedded)
AucUtilScanButton, v5.21c.5521.5403(5.21c/embedded)
AucUtilScanFinish, v5.21c.5521.5515(5.21c/embedded)
AucUtilScanProgress, v5.21c.5521.4979(5.21c/embedded)
AucUtilScanStart, v5.21c.5521.5347(5.21c/embedded)
AucUtilSearchUI, v5.21c.5521.5515(5.21c/embedded)
AucUtilSimpleAuction, v5.21c.5521.5514(5.21c/embedded)
AucUtilVendMarkup, v5.21c.5521.4828(5.21c/embedded)
Babylonian, v5.1.DEV.332(/embedded)
BadBoy, v12.509
BagBrother, v6.0.16
Bagnon, v6.0.16
Bazooka, vv2.4.2
BeanCounter, v5.21c.5521 (SanctimoniousSwamprat)
ButtonForge, v0.9.38
Carbonite, v6.0.1
CarboniteInfo, v1.0
CarboniteNotes, v1.1
CarboniteNotesSample, v1.0
CarboniteQuests, v1.0
CarboniteSocial, v1.0
CarboniteWarehouse, v1.0
CarboniteWeekly, v1.0
Configator, v5.1.DEV.376(/embedded)
DebugLib, v5.1.DEV.337(/embedded)
Enchantrix, v5.21c.5521 (SanctimoniousSwamprat)
EnchantrixBarker, v5.21c.5521 (SanctimoniousSwamprat)
GatherMate2, v1.33.4
Grail, v067
HealBot, v6.0.3.9
HealBotTips, v6.0.3.9
Informant, v5.21c.5521 (SanctimoniousSwamprat)
LibExtraTip, v5.12.DEV.363(/embedded)
MineOMatic, v6.0.3.007
MogIt, v3.4.0
MyBits, v
NugComboBar, v
omouse, v0.1.4
Pawn, v1.9.12
Postal, v3.5.1
Prat30, v3.5.11
Prat30Libraries, v
QuestCompletist, v101
Skada, v1.4-28
Stubby, v5.21c.5521 (SanctimoniousSwamprat)
TheUndermineJournal, v3.3.20150117
TipHelper, v5.12.DEV.351(/embedded)
TomTom, vv60000-1.1.1
WIM, v3.6.23
WoWPro, v6.0.3J
WoWProAchievements, v6.0.3J
WoWProDailies, v6.0.3J
WoWProLeveling, v6.0.3J
WowProProfession, v6.0.3J
WoWProRecorder, v6.0.0
WoWProWorldEvents, v6.0.3J
BlizRuntimeLib_enUS v6.0.3.60000
(ck=b6d)

I could not reproduce the bug you saw, but examining the line that failed convinced me I must have had too much to drink when I wrote that line of code.

So I fixed a problem, but perhaps not your problem.