When comparing items from the inventory with items on the character it generates an error which "stacks" by the dozen with each moment we hold shift to compare items.

1866x ConvertRatings/ConvertRatings.lua:296: attempt to call method 'GetItem' (a nil value)
[string "@ConvertRatings/ConvertRatings.lua"]:296: in function <ConvertRatings/ConvertRatings.lua:228>
[string "=(tail call)"]: ?
[string "=[C]"]: in function securecallfunction' [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:60: in function <SharedXML/Tooltip/TooltipDataHandler.lua:55> [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:80: in function <SharedXML/Tooltip/TooltipDataHandler.lua:76> [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:116: in function <SharedXML/Tooltip/TooltipDataHandler.lua:106> [string "=[C]"]: in function SetAttribute'
[string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:141: in function <SharedXML/Tooltip/TooltipDataHandler.lua:134>
[string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:282: in function <SharedXML/Tooltip/TooltipDataHandler.lua:240>
[string "=[C]"]: in function securecallfunction' [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:237: in function ProcessInfo'
[string "@SharedXML/Tooltip/TooltipComparisonManager.lua"]:249: in function SetItemTooltip' ... [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:49: in function <SharedXML/Tooltip/TooltipDataHandler.lua:44> [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:71: in function <SharedXML/Tooltip/TooltipDataHandler.lua:67> [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:135: in function <SharedXML/Tooltip/TooltipDataHandler.lua:134> [string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:282: in function <SharedXML/Tooltip/TooltipDataHandler.lua:240> [string "=[C]"]: in function securecallfunction'
[string "@SharedXML/Tooltip/TooltipDataHandler.lua"]:237: in function <SharedXML/Tooltip/TooltipDataHandler.lua:236>
[string "=(tail call)"]: ?
[string "@FrameXML/ContainerFrame.lua"]:1504: in function `UpdateTooltip'
[string "@FrameXML/GameTooltip.lua"]:498: in function <FrameXML/GameTooltip.lua:491>
[string "=[C]"]: ?

Locals:
self = ShoppingTooltip1 {
0 =
SetQuestLogRewardSpell = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
GetBackdropColor = defined @SharedXML/Backdrop.lua:390
SetHyperlink = defined =[C]:-1
SetAzeriteEssence = defined =[C]:-1
SetVoidDepositItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetSocketGem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
ClearBackdrop = defined @SharedXML/Backdrop.lua:282
SetLootCurrency = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetLootItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetQuestLogSpecialItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetRecipeReagentItem = defined =[C]:-1
SetMerchantItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
BottomOverlay = Texture {
}
SetSocketedRelic = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
ProcessInfo = defined @SharedXML/Tooltip/TooltipDataHandler.lua:236
NineSlice = Frame {
}
SetInventoryItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
TopEdge = Texture {
}
SetUnitDebuffByAuraInstanceID = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetBagItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetBackdropColor = defined @TipTac/ttCore.lua:1692
LeftEdge = Texture {
}
SetCurrencyByID = defined =[C]:-1
SetSpellBookItem = defined =[C]:-1
textLeft1Font = "GameFontNormalSmall"
SetShapeshift = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
hasMoney = 1
SetArtifactPowerByID = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
textRight2Font = "GameFontHighlightSmall"
TopOverlay = Texture {
}
SetSocketedItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetUnitDebuff = defined =[C]:-1
SetMountBySpellID = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetBorderBlendMode = defined @SharedXML/Backdrop.lua:266
SetToyByItemID = defined =[C]:-1
TextLeft1 = ShoppingTooltip1TextLeft1 {
}
GetTooltipData = defined @SharedXML/Tooltip/TooltipDataHandler.lua:344
SetLFGDungeonShortageReward = defined =[C]:-1
OnBackdropSizeChanged = defined @SharedXML/Backdrop.lua:182
SetArtifactItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetPossession = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetAzeriteEssenceSlot = defined =[C]:-1
SetUnitBuffByAuraInstanceID = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetConduit = defined =[C]:-1
SetupPieceVisuals = defined @SharedXML/Backdrop.lua:246
SetMinimapMouseover = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetQuestLogCurrency = defined =[C]:-1
SetRecipeResultItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetQuestPartyProgress = defined =[C]:-1
ProcessLineData = defined @SharedXML/Tooltip/TooltipDataHandler.lua:303
OnBackdropLoaded = defined @SharedXML/Backdrop.lua:152
SetPvpTalent = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetRuneforgeResultItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetUnit = defined =[C]:-1
SetTotem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
SetVoidWithdrawalItem = defined @SharedXML/Tooltip/TooltipDataHandler.lua:444
ttSetBackdropBorderColorLocked = true
S

Known issue, see #40