WowAce

What exactly is wrong?

 Get an error when mousing over the recipes in the list entry window.

What steps will reproduce the problem?
1. Open a profession

2. Click Scan button to bring up list entry window

3. Mouse over a recipe

What version of the product are you using?

 9.1.0.1

Any additional information?

If you get an error, please paste the ENTIRE thing here:

4x ...Ons\AckisRecipeList\libs\LibQTip-1.0\LibQTip-1.0-48.lua:543: attempt to call method 'GetBackdrop' (a nil value)
[string "@AckisRecipeList\libs\LibQTip-1.0\LibQTip-1.0-48.lua"]:543: in function <...Ons\AckisRecipeList\libs\LibQTip-1.0\LibQTip-1.0.lua:539>
[string "@AckisRecipeList\libs\LibQTip-1.0\LibQTip-1.0-48.lua"]:132: in function `Acquire'
[string "@AckisRecipeList\List.lua"]:855: in function <AckisRecipeList\List.lua:841>
[string "@AckisRecipeList\List.lua"]:937: in function <AckisRecipeList\List.lua:928>
[string "@AckisRecipeList\List.lua"]:233: in function <AckisRecipeList\List.lua:229>

Locals:
tooltip = <unnamed> {
0 = <userdata>
scrollChild = <unnamed> {
}
scrollFrame = <unnamed> {
}
}
key = "Ackis Recipe List Tooltip"
(*temporary) = nil
(*temporary) = GameTooltip {
0 = <userdata>
layoutType = "TooltipDefaultLayout"
TextLeft1 = GameTooltipTextLeft1 {
}
ItemTooltip = <unnamed> {
}
BottomOverlay = <unnamed> {
}
textRight1Font = "GameTooltipHeaderText"
NineSlice = <unnamed> {
}
textLeft2Font = "GameTooltipText"
comparing = false
TextRight2 = GameTooltipTextRight2 {
}
TextLeft2 = GameTooltipTextLeft2 {
}
TopOverlay = <unnamed> {
}
waitingForData = false
shoppingTooltips = <table> {
}
needsReset = true
updateTooltipTimer = 0.116000
textRight2Font = "GameTooltipText"
TextRight1 = GameTooltipTextRight1 {
}
textLeft1Font = "GameTooltipHeaderText"
}
(*temporary) = "attempt to call method 'GetBackdrop' (a nil value)"
GameTooltip = GameTooltip {
0 = <userdata>
layoutType = "TooltipDefaultLayout"
TextLeft1 = GameTooltipTextLeft1 {
}
ItemTooltip = <unnamed> {
}
BottomOverlay = <unnamed> {
}
textRight1Font = "GameTooltipHeaderText"
NineSlice = <unnamed> {
}
textLeft2Font = "GameTooltipText"
comparing = false
TextRight2 = GameTooltipTextRight2 {
}
TextLeft2 = GameTooltipTextLeft2 {
}
TopOverlay = <unnamed> {
}
waitingForData = false
shoppingTooltips = <table> {
}
needsReset = true
updateTooltipTimer = 0.116000
textRight2Font = "GameTooltipText"
TextRight1 = GameTooltipTextRight1 {
}
textLeft1Font = "GameTooltipHeaderText"
}
AcquireTable = <function> defined @AckisRecipeList\libs\LibQTip-1.0\LibQTip-1.0.lua:519
labelProvider = <table> {
cells = <table> {
}
cellMetatable = <table> {
}
cellPrototype = <table> {
}
heap = <table> {
}
}
CELL_MARGIN_H = 6
CELL_MARGIN_V = 3
ResetTooltipSize = <function> defined @AckisRecipeList\libs\LibQTip-1.0\LibQTip-1.0.lua:865

I can backup that I am getting the identical error today, from the exact same activity. Here is the error text from mine:

Message: Interface\AddOns\AckisRecipeList\Interface\List.lua:908: attempt to call method 'GetBackdrop' (a nil value)
Time: Sun Nov 7 19:55:18 2021
Count: 18
Stack: Interface\AddOns\AckisRecipeList\Interface\List.lua:908: attempt to call method 'GetBackdrop' (a nil value)
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:908: in function <Interface\AddOns\AckisRecipeList\Interface\List.lua:841>
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:937: in function <Interface\AddOns\AckisRecipeList\Interface\List.lua:928>
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:233: in function <Interface\AddOns\AckisRecipeList\Interface\List.lua:229>
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:735: in function `Update'
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:226: in function <Interface\AddOns\AckisRecipeList\Interface\List.lua:212>
[string "=[C]"]: in function `SetValue'
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:180: in function <Interface\AddOns\AckisRecipeList\Interface\List.lua:168>
[string "@Interface\AddOns\AckisRecipeList\Interface\List.lua"]:207: in function <Interface\AddOns\AckisRecipeList\Interface\List.lua:206>

Locals: recipe = <table> {
crafted_item_binding = "BIND_ON_PICKUP"
skill_level = 1
crafted_item_id = 142117
recipe_item_binding = "BIND_ON_PICKUP"
Profession = <table> {
}
medium_level = 760
_acquireTypeData = <table> {
}
_localizedName = "Potion of Prolonged Power"
trivial_level = 780
_spellID = 229218
optimal_level = 1
state = 4
item_filter_type = "alchemy_potion"
recipe_item_id = 142120
isValidated = true
_bitflags = <table> {
}
_expansionID = 7
_qualityID = 1
easy_level = 770
}
spellTooltipAnchor = "Right"
acquireTooltipAnchor = "Right"
spellHyperlink = "[Potion of Prolonged Power]"
MainPanel = ARL_MainPanel {
0 = <userdata>
menu_toggle_misc = <unnamed> {
}
xclose_button = <unnamed> {
}
OnBackdropLoaded = <function> defined @Interface\SharedXML\Backdrop.lua:144
GetBackdropColor = <function> defined @Interface\SharedXML\Backdrop.lua:382
current_tab = <unnamed> {
}
expand_button = <unnamed> {
}
SetBackdropBorderColor = <function> defined @Interface\SharedXML\Backdrop.lua:414
profession_texture = ARL_ProfessionButtonPortrait {
}
progress_bar = <unnamed> {
}
menu_toggle_general = <unnamed> {
}
UpdateTitle = <function> defined @Interface\AddOns\AckisRecipeList\Interface\Panel.lua:319
ApplyBackdrop = <function> defined @Interface\SharedXML\Backdrop.lua:286
SetBackdrop = <function> defined @Interface\SharedXML\Backdrop.lua:321
ClearBackdrop = <function> defined @Interface\SharedXML\Backdrop.lua:274
GetBackdropBorderColor = <function> defined @Interface\SharedXML\Backdrop.lua:401
GetBackdrop = <function> defined @Interface\SharedXML\Backdrop.lua:339
bottom_right = <unnamed> {
}
top_left = <unnamed> {
}
expanded_width = 768
menu_toggle_binding = <unnamed> {
}
menu_toggle_rep = <unnamed> {
}
menu_toggle_player = <unnamed> {
}
search_editbox = ARL_SearchBox {
}
normal_width = 384
sort_button = <unnamed> {
}
prof_button = <unnamed> {
}
close_button = AckisRecipeList_CloseButton {
}
SetupTextureCoordinates = <function> defined @Interface\SharedXML\Backdrop.lua:206
OnBackdropSizeChanged = <function> defined @Interface\SharedXML\Backdrop.lua:174
HasBackdropInfo = <function> defined @Interface\SharedXML\Backdrop.lua:270
ToggleState = <function> defined @Interface\AddOns\AckisRecipeList\Interface\Panel.lua:245
menu_toggle_obtain = <unnamed> {
}
filter_menu = <unnamed> {
}
filter_toggle = <unnamed> {
}
GetEdgeSize = <function> defined @Interface\SharedXML\Backdrop.lua:180
menu_toggle_quality = <unnamed> {
}
Display = <function> defined @Interface\AddOns\AckisRecipeList\Interface\Panel.lua:119
title_bar = <unnamed> {
}
list_frame = <unnamed> {
}
is_linked = false
filter_reset = AckisRecipeList_FilterMenuResetButton {
}
menu_toggle_item = <un

LibQtip has a new version that fixes its bug https://www.curseforge.com/wow/addons/libqtip-1-0?page=2

And ackis recipe list uses GetBackdrop which was removed in 9.0.1 and replaced with https://wowpedia.fandom.com/wiki/BackdropTemplate

A quick fix for anyone reading this: I just commented lines 908,909,910 in Interface/List.lua and manually updated LibQtip in the addon libs

@SongZee

Thanks for the tip! This worked for me.

To those in the same boat, when he mentions 'commenting lines', all you need to do is open the file in notepad (Program Filesx86/ WoW/retail/Interface/Addons/AckisRecipeList/Interface) and open the file called List.lua. On the bottom of notepad you'll have a row and column numbers (ie R:908 C:3). Once you're on row 908 just put a set of double dashes ("--") in front. This will "comment" then line which means it's just there to read and doesnt actually execute any code on the line. Do that for the 3 lines, save file, and you're good.

As far as the LibQTip addon goes, I was troubleshooting i downloaded  the LibQtip addon, but it seems this fix works without having to get the extra addon. I disabled LibQTip and it seems to work with or without it. I didn't have to manually update LibQtip or anything like that.