Message: Interface\AddOns\BigDebuffs\BigDebuffs.lua:982: attempt to index field '?' (a nil value)
Time: Wed Feb 10 16:26:29 2021
Count: 3
Stack: Interface\AddOns\BigDebuffs\BigDebuffs.lua:982: attempt to index field '?' (a nil value)
[string "@interface\AddOns\BigDebuffs\BigDebuffs.lua"]:982: in function GetAuraPriority' [string "@Interface\AddOns\BigDebuffs\BigDebuffs.lua"]:1679: in function UNIT_AURA'
[string "@interface\AddOns\BigDebuffs\BigDebuffs.lua"]:552: in function <Interface\AddOns\BigDebuffs\BigDebuffs.lua:552>

Locals: self =

{
NAME_PLATE_UNIT_REMOVED = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:1940
SetDefaultModuleLibraries = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:367
SaveUnitFramePosition = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:680
EnableModule = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:332
modules = {
}
baseName = "BigDebuffs"
IterateEmbeds = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:442
IsDispellable = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:910
SecureHookScript = defined @interface\AddOns\BigDebuffs\Libs\AceHook-3.0\AceHook-3.0.lua:410
IsPriorityBigDebuff = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:1613
IsPriorityDebuff = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:900
PriorityDebuffs = {
}
SetDefaultModulePrototype = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:409
defaultModuleState = true
IsEnabled = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:451
DisableModule = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:350
RegisterMessage = defined @interface\AddOns\Bagnon\common\Wildpants\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:90
UnregisterMessage = defined @interface\AddOns\Bagnon\common\Wildpants\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:153
frames = {
}
hooks = {
}
PLAYER_FOCUS_CHANGED = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:1862
WarningDebuffs = {
}
UNIT_AURA = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:1619
SetEnabledState = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:424
Hook = defined @interface\AddOns\BigDebuffs\Libs\AceHook-3.0\AceHook-3.0.lua:274
enabledState = true
COMBAT_LOG_EVENT_UNFILTERED = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:748
RegisterEvent = defined @interface\AddOns\Bagnon\common\Wildpants\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:90
units = {
}
IterateModules = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:437
AttachNameplate = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:647
RawHook = defined @interface\AddOns\BigDebuffs\Libs\AceHook-3.0\AceHook-3.0.lua:313
AttachUnitFrame = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:543
UNIT_AURA_NAMEPLATE = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:1743
OnInitialize = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:468
NewModule = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:235
GetModule = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:210
AttachedFrames = {
}
defaultModuleLibraries = {
}
options = {
}
specDispel = {
}
Spells = {
}
GetName = defined @interface\AddOns\BigDebuffs\Libs\AceAddon-3.0\AceAddon-3.0.lua:279
UNIT_AURA_ALL_UNITS = defined @interface\AddOns\BigDebuffs\BigDebuffs.lua:794
name = "BigDebuffs"
GetNameplatesPriority = defined @interfac

I have the same issue. Also happens whenever another mage uses alter time. I noticed an empty field when accessing bd settings -> Spells -> Defensive Buffs: the first entry is empty. Hovering over it causes this error:

Message: ...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1518: Usage: AceConfigDialogTooltip:SetText("text" [, color, wrap])
Time: Thu Feb 11 13:12:15 2021
Count: 5
Stack: ...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1518: Usage: AceConfigDialogTooltip:SetText("text" [, color, wrap])
[string "=[C]"]: in function SetText' [string "@Interface\AddOns\BigDebuffs\Libs\AceConfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua"]:1518: in function <...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1486> [string "=[C]"]: ? [string "@Interface\AddOns\BigDebuffs\Libs\AceGUI-3.0\AceGUI-3.0.lua"]:72: in function <...ace\AddOns\BigDebuffs\Libs\AceGUI-3.0\AceGUI-3.0.lua:70> [string "@Interface\AddOns\BigDebuffs\Libs\AceGUI-3.0\AceGUI-3.0.lua"]:306: in function Fire'
[string "@interface\AddOns\BigDebuffs\Libs\AceGUI-3.0\widgets\AceGUIContainer-TreeGroup.lua"]:206: in function <...ibs\AceGUI-3.0\widgets\AceGUIContainer-TreeGroup.lua:204>

Locals: