When generating bars this error occurs in retail/mop-R:

14x MagicTargets/MagicTargets.lua:1988: bad argument #1 to 'SetJustifyV' (Usage: self:SetJustifyV(justifyV))
[string "=[C]"]: in function SetJustifyV' [string "@MagicTargets/MagicTargets.lua"]:1988: in function SetupBarLabels'
[string "@MagicTargets/MagicTargets.lua"]:2081: in function CreateBar' [string "@MagicTargets/MagicTargets.lua"]:2152: in function ToggleTestBars'
[string "@MagicTargets/MagicTargets.lua"]:1679: in function <MagicTargets/MagicTargets.lua:1678>
[string "=[C]"]: ?
[string "@Bartender4/libs/AceConfig-3.0-3/AceConfigDialog-3.0-86/AceConfigDialog-3.0.lua"]:45: in function <...nfig-3.0/AceConfigDialog-3.0/AceConfigDialog-3.0.lua:43>
[string "@Bartender4/libs/AceConfig-3.0-3/AceConfigDialog-3.0-86/AceConfigDialog-3.0.lua"]:836: in function <...nfig-3.0/AceConfigDialog-3.0/AceConfigDialog-3.0.lua:658>
[string "=[C]"]: ?
[string "@AutoBar/libs/AceGUI-3.0-41/AceGUI-3.0.lua"]:72: in function <AutoBar/libs/AceGUI-3.0/AceGUI-3.0.lua:70>
[string "@AutoBar/libs/AceGUI-3.0-41/AceGUI-3.0.lua"]:306: in function `Fire'
[string "@AutoBar/libs/AceGUI-3.0-41/widgets/AceGUIWidget-CheckBox.lua"]:68: in function <...ar/libs/AceGUI-3.0/widgets/AceGUIWidget-CheckBox.lua:57>

Locals:
(*temporary) = FontString {
0 =
}
(*temporary) = "CENTER"

You can add the following line in your MagicTargets.lua just before the line 1988.
if data.justifyV == "CENTER" then data.justifyV = "MIDDLE" end
I now get the addon working properly for the bar creations.
Tested in Wow Catalcysm Classic

noted.