LUA for HP % on Nameplates?

[Xancepants]

Hello all!
I've come across this bit of code that puts the % of HP in the center of Nameplates. However, now it starts throwing major errors when you try to type anything in chat and it seems to cause an infinite taint. I was wondering if anybody might know of a way to fix this bit of code so that it works with todays version of WoW? Or possibly even come up with a new way to achieve this? Any help is appreciated, and thank you in advance!


Here is the Lua:

CreateFrame('frame'):SetScript('OnUpdate', function(self, elapsed)
  for index = 1, select('#', WorldFrame:GetChildren()) do
        local f = select(index, WorldFrame:GetChildren())
        if f:GetName() and f:GetName():find('NamePlate%d') then
          f.h = select(1, select(1, f:GetChildren()):GetChildren())
          if f.h then
         if not f.h.v then
           f.h.v = f.h:CreateFontString(nil, "ARTWORK")  
           f.h.v:SetPoint("CENTER", 5, 0)
           f.h.v:SetFont(STANDARD_TEXT_FONT, 9, 'OUTLINE')
         else
           local _, maxh = f.h:GetMinMaxValues()
           local val = f.h:GetValue()
           f.h.v:SetText(string.format(math.floor((val/maxh)*100)).." %")
         end
          end
        end
  end
end)

Here is the Error that Bug Sack is logging:

2269x Custom Settings\Custom Settings.lua:88: Attempt to access forbidden object from code tainted by an AddOn
[C]: in function `GetName'
Custom Settings\Custom Settings.lua:88: in function <Custom Settings\Custom Settings.lua:85>

Locals:
(*temporary) = <unnamed> {
0 = <userdata>
}