Message: ...Ons\tdBattlePetScript\Libs\tdGUI\Widget\DropMenu.lua line 33:
attempt to call method 'SetBackdrop' (a nil value)
Debug:
[string "=[C]"]: SetBackdrop()
[string "@tdBattlePetScript\Libs\tdGUI\Widget\DropMenu.lua"]:33: ctor()
[string "@tdBattlePetScript\Libs\tdGUI\Libs\LibClass-2.0\Class-2.0.lua"]:90:
...PetScript\Libs\tdGUI\Libs\LibClass-2.0\Class-2.0.lua:82
[string "=(tail call)"]: ?
[string "@tdBattlePetScript\Libs\tdGUI\Widget\DropMenu.lua"]:329

Message: ...Ons\tdBattlePetScript\UI\Widgets\AutoCompleteBox.lua line 25:
attempt to call method 'SetBackdrop' (a nil value)
Debug:
[string "=(tail call)"]: ?
[string "@tdBattlePetScript\UI\Widgets\AutoCompleteBox.lua"]:25: ctor()
[string "@tdBattlePetScript\Libs\tdGUI\Libs\LibClass-2.0\Class-2.0.lua"]:90:
...PetScript\Libs\tdGUI\Libs\LibClass-2.0\Class-2.0.lua:82
[string "=(tail call)"]: ?
[string "@tdBattlePetScript\UI\Widgets\ScriptEditor.lua"]:17: ctor()
[string "@tdBattlePetScript\Libs\tdGUI\Libs\LibClass-2.0\Class-2.0.lua"]:90:
...PetScript\Libs\tdGUI\Libs\LibClass-2.0\Class-2.0.lua:82
[string "=(tail call)"]: ?
[string "@tdBattlePetScript\UI\MainPanel.lua"]:234: MakeBox()
[string "@tdBattlePetScript\UI\MainPanel.lua"]:255:
tdBattlePetScript\UI\MainPanel.lua:26
[string "=[C]"]: ?
[string "@ace3\AceAddon-3.0\AceAddon-3.0.lua"]:70:
Ace3\AceAddon-3.0\AceAddon-3.0.lua:65

There is a temp fix in: https://www.curseforge.com/wow/addons/tdbattlepetscript?comment=114