A lua error a got today:

3x ...lvUI_BetterTalentFrame\modules/TalentFrameRework.lua:147: attempt to index field 'bg' (a nil value)
[string "@ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua"]:147: in function UpdateTalentsTab' [string "@ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua"]:183: in function <...lvUI_BetterTalentFrame\modules/TalentFrameRework.lua:180> [string "=(tail call)"]: ? [string "=[C]"]: in function PlayerTalentFrame_Update'
[string "@Blizzard_TalentUI\Blizzard_TalentUI.lua"]:429: in function PlayerTalentFrame_Refresh' [string "@Blizzard_TalentUI\Blizzard_TalentUI.lua"]:1018: in function PlayerSpecTab_OnClick'
[string "@Blizzard_TalentUI\Blizzard_TalentUI.lua"]:270: in function <...rfaceBlizzard_TalentUI\Blizzard_TalentUI.lua:257>
[string "=[C]"]: ?
[string "=[C]"]: in function Show' [string "@FrameXML\UIParent.lua"]:2893: in function SetUIPanel'
[string "@FrameXML\UIParent.lua"]:2738: in function ShowUIPanel' [string "@FrameXML\UIParent.lua"]:2606: in function <FrameXML\UIParent.lua:2602> [string "=[C]"]: in function SetAttribute'
[string "@FrameXML\UIParent.lua"]:3457: in function ShowUIPanel' [string "@Blizzard_TalentUI\Blizzard_TalentUI.lua"]:117: in function PlayerTalentFrame_Toggle'
[string "@FrameXML\UIParent.lua"]:851: in function <FrameXML\UIParent.lua:844>
[string "=[C]"]: in function `ToggleTalentFrame'
[string "TOGGLETALENTS"]:1: in function <[string "TOGGLETALENTS"]:1>

Locals:
self =

{
PLAYER_LOGOUT = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:252
SetDefaultModuleLibraries = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:367
UpdateActivateButton = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:82
Enable = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:294
NewModule = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:235
EnableModule = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:332
modules = {
}
GetModule = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:210
IterateEmbeds = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:442
SecureHookScript = defined @ace3\AceHook-3.0\AceHook-3.0.lua:410
defaultModuleLibraries = {
}
RawHookScript = defined @ace3\AceHook-3.0\AceHook-3.0.lua:395
PLAYER_ENTERING_WORLD = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:256
UpdateSpecTab = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:92
selectedSpec = 1
PLAYER_SPECIALIZATION_CHANGED = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:248
GetName = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:279
UpdateTalentCache = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:53
baseName = "ElvUI_BetterTalentFrame"
hasRunOneTime = true
name = "ElvUI_BetterTalentsFrame_TalentFrameRework"
Initialize = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:281
IsEnabled = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:451
orderedModules = {
}
SecureHook = defined @ace3\AceHook-3.0\AceHook-3.0.lua:336
DisableModule = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:350
InitActivateButton = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:188
GetTalentButtonTexture = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:48
UpdateTalentsTab = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:103
Unhook = defined @ace3\AceHook-3.0\AceHook-3.0.lua:418
RegisterMessage = defined @LibSharedMedia-3.0\CallbackHandler-1.0\CallbackHandler-1.0.lua:90
HookScript = defined @ace3\AceHook-3.0\AceHook-3.0.lua:366
Update = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:180
GetTalentButtonFrame = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:43
IsHooked = defined @ace3\AceHook-3.0\AceHook-3.0.lua:493
UnregisterMessage = defined @LibSharedMedia-3.0\CallbackHandler-1.0\CallbackHandler-1.0.lua:153
VerifyDB = defined @ElvUI_BetterTalentFrame\modules/TalentFrameRework.lua:21
IsModule = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:217
defaultModuleState = true
SetDefaultModuleState = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:387
UnregisterAllEvents = defined @LibSharedMedia-3.0\CallbackHandler-1.0\CallbackHandler-1.0.lua:174
SendMessage = defined @LibSharedMedia-3.0\CallbackHandler-1.0\CallbackHandler-1.0.lua:59
SetEnabledState = defined @ElvUI\Libraries\Ace3\AceAddon-3.0\AceAddon-3.0.lua:424
Hook = <f