WoWInterface - Addon creating SoulShard Bar

I had an addon creating a SoulShard bar fro Afflic locks pre-7.0

I have updated it so that is shows and (seems) to work without issue for all Lock specs, however.. I get this error:

Code:

Message: ...terface\AddOns\oUF_Diablo\modules\oUF_SoulShards.lua:49: attempt to index local 'orb' (a nil value)

Time: 07/29/16 14:12:44

Count: 3

Stack: ...terface\AddOns\oUF_Diablo\modules\oUF_SoulShards.lua:49: in function <...terface\AddOns\oUF_Diablo\modules\oUF_SoulShards.lua:11>

(tail call): ?

(tail call): ?

...terface\AddOns\oUF_Diablo\modules\oUF_SoulShards.lua:67: in function <...terface\AddOns\oUF_Diablo\modules\oUF_SoulShards.lua:57>

(tail call): ?

The function in which it refers to is:

Lua Code:

local Update = function(self, event, unit, powerType)
  local bar = self.SoulShardPowerBar
  local cur = UnitPower(unit, SPELL_POWER_SOUL_SHARDS)
  local max = UnitPowerMax(unit, SPELL_POWER_SOUL_SHARDS)
  --[[ --do not hide the bar when the value is empty, keep it visible
  if cur < 1 then
    if bar:IsShown() then bar:Hide() end
    return
  else
    if not bar:IsShown() then bar:Show() end
  end
  ]]
  --adjust the width of the soulshard power frame
  local w = 64*(max+1)
  bar:SetWidth(w)
  for i = 1, bar.maxOrbs do
    local orb = self.SoulShards[i]
    if i > max then
       if orb:IsShown() then orb:Hide() end
    else
      if not orb:IsShown() then orb:Show() end
    end
  end
  for i = 1, max do
    local orb = self.SoulShards[i]
    local full = cur/max
    if(i <= cur) then
      if full == 1 then
        orb.fill:SetVertexColor(1,0,0)
        orb.glow:SetVertexColor(1,0,0)
      else
        orb.fill:SetVertexColor(bar.color.r,bar.color.g,bar.color.b)
        orb.glow:SetVertexColor(bar.color.r,bar.color.g,bar.color.b)
      end
      orb.fill:Show()
      orb.glow:Show()
      orb.highlight:Show()
    else
      orb.fill:Hide()
      orb.glow:Hide()
      orb.highlight:Hide()
    end
  end

Line 49 being the "orb.fill:Hide()" line in the else condition at the end. Commenting out that leads me to line 50, then 51.
Commenting all 3 of those out removes the error, however it breaks the addon.

With the lines commented out, the soul shards are added to the bar as they are built, but are not removed when consumed.
Not commented out, the soul shards are removed from the bar as expected, but I am spammed with this error countless times while in combat.

Since it's returning with an error, it is also affecting other aspects of the UI addon I have built this into, so leaving the lines and ignoring the errors is not really an option.