Still getting the tooltip, but on logon I get the below, using v28

Message: ...face\AddOns\Blizzard_Deprecated\Deprecated_9_1_0.lua:91: attempt to call global 'SetCVarBool' (a nil value)
Time: Wed Jun 30 17:55:56 2021
Count: 1
Stack: ...face\AddOns\Blizzard_Deprecated\Deprecated_9_1_0.lua:91: attempt to call global 'SetCVarBool' (a nil value)
[string "=[C]"]: in function SetCVarBool' [string "@Interface\AddOns\Blizzard_Deprecated\Deprecated_9_1_0.lua"]:91: in function SetShowMissingSourceInItemTooltips'
[string "@interface\AddOns\AppearanceTooltip\addon.lua"]:69: in function `?'
[string "@interface\AddOns\AppearanceTooltip\addon.lua"]:20: in function <Interface\AddOns\AppearanceTooltip\addon.lua:19>

Locals:

Keep up the great work, love this addon