What steps will reproduce the problem?
1. Have WIM open in WoW
2. Message someone from Battle.net - I used a RealID friend.

What is the expected output? What do you see instead?
Get a nice WIM error (below).
I have 3 tabs now for the same person, none of which has the full conversation - sending to the person goes to 1 tab, receiving goes to another, and every message results in the error popping up.

What version of the product are you using?
3.6.23

Do you have an error log of what happened?

14x WIM\Modules\History-History.lua:83 table index is nil
WIM\Modules\History-History.lua:83 in function <WIM\Modules\History.lua:76
WIM\Modules\History-History.lua:135 in function <WIM\Modules\History.lua:122
WIM\Modules\History-History.lua:158 in function `fun'
WIM\WIM-3.6.23.lua:293 in function `CallModuleFunction'
WIM\Modules\WhisperEngine.lua:385 in function `handler'
...s\WIM\Libs\LibChatHandler-1.0\LibChatHandler-1.0-23.lua:274 in function <...s\WIM\Libs\LibChatHandler-1.0\LibChatHandler-1.0.lua:259
...s\WIM\Libs\LibChatHandler-1.0\LibChatHandler-1.0-23.lua:326 in function <...s\WIM\Libs\LibChatHandler-1.0\LibChatHandler-1.0.lua:314

Locals:
inbound = false
msg = "horde?"
from = nil
db = <table> {
 friends = true
 all = false
 guild = true
}
win = WIM3_msgFrame1 {
 0 = <userdata>
 Hide_Normal = <function> defined =[C]:-1
 class = ""
 isNew = false
 msgSent = false
 level = ""
 Hide = <function> defined @WIM\Sources\WindowHandler.lua:1137
 animation = <table> {
 }
 Pop = <function> defined @WIM\Sources\WindowHandler.lua:1023
 isWimWindow = true
 age = 958946.282
 msgWaiting = true
 SetScale = <function> defined @WIM\Sources\WindowHandler.lua:767
 SafeGetTop = <function> defined @WIM\Sources\WindowHandler.lua:1185
 AddMessage = <function> defined @WIM\Sources\WindowHandler.lua:864
 helperFrame = WIM_WindowHelperFrame {
 }
 SafeGetRight = <function> defined @WIM\Sources\WindowHandler.lua:1182
 UpdateIcon = <function> defined @WIM\Sources\WindowHandler.lua:886
 guild = ""
 lastDate = "01/06/2015"
 customSize = false
 UpdateProps = <function> defined @WIM\Sources\WindowHandler.lua:1088
 SetScale_Orig = <function> defined =[C]:-1
 GetRuleSet = <function> defined @WIM\Sources\WindowHandler.lua:1013
 bn = <table> {
 }
 race = ""
 lastActivity = 958946.282
 theUser = "|Kf289|k0|k"
 isHistory = true
 AddEventMessage = <function> defined @WIM\Sources\WindowHandler.lua:875
 classColor = "ffffff"
 isBN = true
 initialized = true
 type = "whisper"
 ResetAnimation = <function> defined @WIM\Sources\WindowHandler.lua:1165
 hasMoved = false
 SafeGetLeft = <function> defined @WIM\Sources\WindowHandler.lua:1179
 AddMessageRaw = <function> defined @WIM\Sources\WindowHandler.lua:871
 widgets = <table> {
 }
 SafeGetBottom = <function> defined @WIM\Sources\WindowHandler.lua:1188
 online = true
 isParent = true
 SendWho = <function> defined @WIM\Sources\WindowHandler.lua:948
 WhoCallback = <function> defined @WIM\Sources\WindowHandler.lua:936
 UpdateCharDetails = <function> defined @WIM\Sources\WindowHandler.lua:932
}
pid = 289
_G = <table> {
 ContainerFrame5Item7 = ContainerFrame5Item7 {
 }
 MultiCastActionButton6Cooldown = MultiCastActionButton6Cooldown {
 }
 MerchantItem9ItemButtonStock = MerchantItem9ItemButtonStock {
 }
 GetTrainerServiceTypeFilter = <function> defined =[C]:-1
 UNIT_NAMES_COMBATLOG_TOOLTIP = "Color unit names."
 UNIT_NAMEPLATES_TYPE_TOOLTIP_3 = "This method avoids overlapping nameplates by spreading them out horizontally and vertically."
 SetTrainerServiceTypeFilter = <function> defined =[C]:-1
 SPELL_FAILED_CUSTOM_ERROR_71 = "This partygoer wants to dance with you."
 BT4Button58 = BT4Button58 {
 }
 RecruitAFriendFrame = RecruitAFriendFrame {
 }
 CompactUnitFrameProfilesGeneralOptionsFrameHealthTextDropdownButtonNormalTexture = CompactUnitFrameProfilesGeneralOptionsFrameHealthTextDropdownButtonNormalTexture {
 }
 TutorialFrameLeft19 = TutorialFrameLeft19 {
 }
 MultiCastActionButton2Cooldown = MultiCastActionButton2Cooldown {
 }
 ERR_TRADE_EQUIPPED_BAG = "You can't trade equipped bags."
 PVP_RANK_6_1 = "Corporal"
 BOOKTYPE_PROFESSION = "professions"
 AudioOptionsVoicePanelOutputDeviceDropDownButtonHighlightTexture = AudioOptionsVoicePanelOutputDeviceDropDownButtonHighlightTexture {
 }
 InterfaceOptionsDisplayPanelShowAggroPercentageText = InterfaceOptionsDisplayPanelShowAggroPercentageText {
 }
 VideoOptionsFrameCategoryFrameButton17ToggleHighlightTexture = VideoOptionsFrameCategoryFrameButton17ToggleHighlightTexture {
 }
 MerchantItem3AltCurrencyFrameItem1Text = MerchantItem3AltCurrencyFrameItem1Text {
 }
 OPTION_TOOLTIP_ACTION_BUTTON_USE_KEY_DOWN = "Action button keybinds will respond on key down, rather than on key up."
 BINDING_NAME_NAMEPLATES = "Show Enemy Name Plates"
 INSTANCE_UNAVAILABLE_OTHER_TEMPORARILY_DISABLED = "%s cannot enter. This instance is temporarily disabled."
 Atr_StackList9 = Atr_StackList9 {
 }
 IsReferAFriendLinked = <function> defined =[C]:-1
 MAIL_LET