With only spartanUI/bartender/questie running as addons (or with anything else), I get a very common set of errors upon starting combat and then completely flooded with errors once the loot window opens...mostly the same one over and over again (Error 00000244D011E4A0):

C stack overflow
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
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...
[C]: ?
[C]: in function GameTooltip_SetBackdropStyle' Interface\FrameXML\GameTooltip.lua:540: in function GameTooltip_UpdateStyle'
Interface\FrameXML\GameTooltip.lua:551: in function <Interface\FrameXML\GameTooltip.lua:543>
[C]: ?
[C]: ?
[C]: ?
[C]: in function SetLootItem' Interface\FrameXML\LootFrame.lua:358: in function LootItem_OnEnter'
[string ":OnUpdate"]:2: in function <[string ":OnUpdate"]:1>
(*temporary) = GameTooltip {
0 =
numMoneyFrames = 2
shoppingTooltips =

{
}
SetQuestLogItem = defined =[C]:-1
BottomOverlay = {
}
updateTooltip = 0.167000
comparing = false
__tamedCounts = false
SetBorderColor = defined @interface\AddOns\SpartanUI\modules\Tooltips.lua:194
TopOverlay = {
}
SUITip = {
}
needsReset = true
SetQuestItem = defined =[C]:-1
hasMoney = 1
}
(*temporary) = {
backdropColor = {
}
bgFile = "Interface/Tooltips/UI-Tooltip-Background"
tile = true
backdropBorderColor = {
}
tileSize = 16
edgeFile = "Interface/Tooltips/UI-Tooltip-Border"
tileEdge = true
edgeSize = 16
insets = {
}
}
(*temporary) = defined @interface\FrameXML\GameTooltip.lua:422
(*temporary) = GameTooltip {
0 =
numMoneyFrames = 2
shoppingTooltips = {
}
SetQuestLogItem = defined =[C]:-1
BottomOverlay = {
}
updateTooltip = 0.167000
comparing = false
__tamedCounts = false
SetBorderColor = defined @interface\AddOns\SpartanUI\modules\Tooltips.lua:194
TopOverlay = {
}
SUITip = {
}
needsReset = true
SetQuestItem = defined =[C]:-1
hasMoney = 1
}
(*temporary) = {
backdropColor = {
}
bgFile = "Interface/Tooltips/UI-Tooltip-Background"
tile = true
backdropBorderColor = {
}
tileSize = 16
edgeFile = "Interface/Tooltips/UI-Tooltip-Border"
tileEdge = true
edgeSize = 16
insets = {
}
}
= defined @interface\FrameXML\GameTooltip.lua:422
= defined @interface\AddOns\SpartanUI\modules\Tooltips.lua:509