1.6.6（Vanilla）appears one bug as follows：
Message: Interface\AddOns\Blizzard_InspectUI\Localization.lua:8: attempt to index global 'InspectTalentFrameSpentPoints' (a nil value)
Time: Thu Sep 29 19:36:38 2022
Count: 1
Stack: Interface\AddOns\Blizzard_InspectUI\Localization.lua:8: attempt to index global 'InspectTalentFrameSpentPoints' (a nil value)
[string "@interface\AddOns\Blizzard_InspectUI\Localization.lua"]:8: in main chunk
[string "=[C]"]: in function LoadAddOn' [string "@Interface_Vanilla\FrameXML\UIParent.lua"]:365: in function UIParentLoadAddOn'
[string "@Interface_Vanilla\FrameXML\UIParent.lua"]:400: in function InspectFrame_LoadUI' [string "@Interface_Vanilla\FrameXML\UIParent.lua"]:636: in function InspectUnit'
[string "@Interface_Vanilla\FrameXML\UnitPopup.lua"]:1692: in function func' [string "@Interface\FrameXML\UIDropDownMenu.lua"]:942: in function UIDropDownMenuButton_OnClick'
[string ":OnClick"]:1: in function <[string ":OnClick"]:1>

Locals: (*temporary) = nil
(*temporary) = nil
(*temporary) = 1
(*temporary) = 2
(*temporary) = "InspectFrameTab2"
(*temporary) = defined =[C]:-1
(*temporary) = InspectFrameTab2Text {
0 =
}
(*temporary) = "CENTER"
(*temporary) = "InspectFrameTab2"
(*temporary) = "CENTER"
(*temporary) = 0
(*temporary) = 5
(*temporary) = "attempt to index global 'InspectTalentFrameSpentPoints' (a nil value)"
Message: (null)
Time: Thu Sep 29 19:36:38 2022
Count: 3

This is an issue with the Blizzard interface files and not a result of using ShestakUI.