Get this string most of time i open a profession.

Auctionator\AuctionatorHints.lua:768: attempt to concatenate local 'name' (a nil value)
[string "@Auctionator\AuctionatorHints.lua"]:768: in function Atr_Tooltip_AddLine' [string "@Auctionator\AuctionatorHints.lua"]:523: in function Atr_STWP_AddVendorInfo'
[string "@Auctionator\AuctionatorHints.lua"]:745: in function ReagentLine' [string "@Auctionator\AuctionatorHints.lua"]:721: in function Atr_ShowReagentTooltip'
[string "@Auctionator\AuctionatorHints.lua"]:75: in function <Auctionator\AuctionatorHints.lua:72>
[string "=[C]"]: in function baseSetTradeSkillItem' [string "@SigmaProfessionFilterCooking\SigmaProfessionFilterCooking.lua"]:26: in function <...essionFilterCooking\SigmaProfessionFilterCooking.lua:23> [string "=(tail call)"]: ? [string "@SigmaProfessionFilter\TradeSkillFrame\Core\DefineFunctions.lua"]:49: in function GetNumTradeSkills'
[string "@SigmaProfessionFilter\TradeSkillFrame\Core\Utility.lua"]:384: in function FullUpdate' [string "@SigmaProfessionFilter\TradeSkillFrame\Core\Utility.lua"]:266: in function <...gmaProfessionFilter\TradeSkillFrame\Core\Utility.lua:215> [string "=[C]"]: ? ... [string "=[C]"]: ? [string "=[C]"]: ? [string "=[C]"]: in function UseAction'
[string "@FrameXML\SecureTemplates.lua"]:338: in function `handler'
[string "@FrameXML\SecureTemplates.lua"]:616: in function <FrameXML\SecureTemplates.lua:564>
[string "=[C]"]: ?
[string "@FrameXML\SecureHandlers.lua"]:266: in function <FrameXML\SecureHandlers.lua:263>
[string "=[C]"]: ?
[string "@FrameXML\SecureHandlers.lua"]:296: in function <FrameXML\SecureHandlers.lua:279>
[string "=(tail call)"]: ?

Locals:
tip = {
BottomLeftCorner = {
}
OnBackdropLoaded = defined @SharedXML\Backdrop.lua:239
backdropBorderColor =

{
}
GetBackdropColor = defined @SharedXML\Backdrop.lua:477
TopLeftCorner = {
}
RightEdge = {
}
ApplyBackdrop = defined @SharedXML\Backdrop.lua:381
SetBackdrop = defined @SharedXML\Backdrop.lua:416
ClearBackdrop = defined @SharedXML\Backdrop.lua:369
TopOverlay = {
}
GetBackdropBorderColor = defined @SharedXML\Backdrop.lua:496
GetBackdrop = defined @SharedXML\Backdrop.lua:434
SetBorderBlendMode = defined @SharedXML\Backdrop.lua:353
LocalTooltips = {
}
SetupTextureCoordinates = defined @SharedXML\Backdrop.lua:301
OnBackdropSizeChanged = defined @SharedXML\Backdrop.lua:269
HasBackdropInfo = defined @SharedXML\Backdrop.lua:365
0 =
GetEdgeSize = defined @SharedXML\Backdrop.lua:275
updateTooltip = 0.200000
TopRightCorner = {
}
TopEdge = {
}
backdropColor = {
}
Center = {
}
BottomOverlay = {
}
backdropInfo = {
}
BottomEdge = {
}
SetBackdropBorderColor = defined @SharedXML\Backdrop.lua:509
needsReset = true
SetupPieceVisuals = defined @SharedXML\Backdrop.lua:333
SetBackdropColor = defined @SharedXML\Backdrop.lua:486
LeftEdge = {
}
BottomRightCorner = {
}
}
lefttext = "Vendor"
new_leftext = "Vendor"
new_righttext = "|cFFFFFFFF12|TMoneyFrame\UI-SilverIcon:12:12:4:0|t 50|TMoneyFrame\UI-CopperIcon:12:12:4:0|t"
doreplace = 0
name = nil
numlines = 5
found = false
(for index) = 1
(for limit) = 5
(for step) = 1
i = 1
(*temporary) = {
NL_DropDown084 = NL_DropDown084 {
}
ContainerFrame5Item7 = ContainerFrame5Item7 {
}
DH_HAVOC_CORE_ABILITY_2 = "Strong melee attack that consumes Fury. If it critical strikes, some Fury is refunded."
BT4Button85Shine14 = BT4Button85Shine14 {
}
GetTrainerServiceTypeFilter = defined =[C]:-1
UNIT_NAMES_COMBATLOG_TOOLTIP = "Color unit names."
AchievementFrameStatsBG = AchievementFrameStatsBG {
}
SetTrainerServiceTypeFilter = defined =[C]:-1
LE_GAME_ERR_CHAT_RAID_RESTRICTED_TRIAL = 773
SPELL_FAILED_CUSTOM_ERROR_71 = "This partygoer wants to dance with you."
LE_GAME_ERR_PET_SPELL_TARGETS_DEAD = 399
BT4Button58 = BT4Button58 {
}
Atr_StackPriceCopperMiddle = Atr_StackPriceCopperMiddle {
}
CompactUnitFrameProfilesGeneralOptionsFrameHealthTextDropdownButtonNormalTexture = CompactUnitFrameProfilesGeneralOptionsFrameHealthTextDropdownButtonNormalTexture {
}
TitanPanelTITAN_REPUTATION_XPButtonRightClickMenuIcon = TitanPanelTITAN_REPUTATION_XPButtonRightClickMenuIcon {
}
LootReserveServerImportWindowIcon = LootReserveServerImportWindowIcon {
}
PawnItemComparer = defined @Pawn\Pawn.lua:3901
GRM_ToolIgnoredScrollBorderFrameBottomBorder = GRM_ToolIgnoredScrollBorderFrameBottomBorder {
}
MultiBarLeftButton7 = MultiBarLeftButton7 {
}
InterfaceOptionsNamesPanelUnitNameplatesShowAll = InterfaceOptionsNamesPanelUnitNameplatesShowAll {
}
NL_DropDown045DisabledTexture = NL_DropDown045DisabledTexture {
}
LE_GAME_ERR_INVALID_FOLLOW_PVP_COMBAT = 353
MerchantItem6AltCurrencyFrameItem1Text = MerchantItem6AltCurrencyFrameItem1Text {
}
BINDING_NAME_NAMEPLATES = "Show Enemy Name Plates"
CHAT_HEADER_SUFFIX = ": "
MultiBarBottomRightButton8Shine5 = MultiBarBottomRightButton8Shine5 {
}
IsReferAFriendLinked = defined =[C]:-1
Inst31Quest3Rewardtext = "|cff0070dd No Rewards"
UnitFrameManaBar_UnregisterDefaultEvents = defined @FrameXML\UnitFrame.lua:600
WhatsTrainingFrameRow3Spell = WhatsTrainingFrameRow3Spell {
}
CALENDAR_RAID_RESET_DESCRIPTION = "%1$s resets at %2$s."

ok, an user reported this issue on my discord as well so I took a look and I found out where the issue is,

my addon creates a custom GameTooltip frame that creates issues with this part of Auctionator:

https://github.com/1010101110/Auctionator-classic/blob/master/AuctionatorHints.lua#L761-L778

specifically this is the list of issues I found:

• name = nil
  this line was returning 'nil'
  which then resulted in an issue at this line
  this was happening because my addon creates a frame with a nil name, I already fixed this on my side by adding a name, however implementing a null check shouldn't hurt

• left/right = nil
  even after fixing the "name" these two lines still return nil
  which then results in an issue at these lines
  I am not sure why this is happening, however it should be easily fixed on Auctionator by just adding a null check

if you need more tests on my side let me know, I can also send you a PR if you want