Lua error upon logging in (Guild frame)

Every time I log in I recieve the following error, i have disabled all addons except bug grabber, renamed my wtf folder to test this.

5x Blizzard_FrameXML/GuildUtil.lua:99: attempt to index local 'formatString' (a nil value)
[string "@Blizzard_FrameXML/GuildUtil.lua"]:99: in function <Blizzard_FrameXML/GuildUtil.lua:56>
[string "=[C]"]: in function `GuildNewsButton_SetNews'
[string "@Blizzard_Communities/GuildNews.lua"]:19: in function `Init'
[string "@Blizzard_Communities/GuildNews.lua"]:35: in function `initializer'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua"]:396: in function `InvokeInitializer'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua"]:405: in function `InvokeInitializers'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:718: in function `Update'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:258: in function `SetScrollPercentageInternal'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:184: in function `FullUpdateInternal'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:692: in function `FullUpdateInternal'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:146: in function `FullUpdate'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:663: in function <...ddOns/Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua:662>
[string "=[C]"]: ?
[string "@Blizzard_SharedXML/CallbackRegistry.lua"]:178: in function <...rfaceBlizzard_SharedXML/CallbackRegistry.lua:177>
[string "=[C]"]: ?
[string "@Blizzard_SharedXML/CallbackRegistry.lua"]:181: in function `TriggerEvent'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua"]:342: in function `SignalDataChangeEvent'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua"]:322: in function `SetDataProvider'
[string "@Blizzard_SharedXML/Shared/Scroll/ScrollBox.lua"]:647: in function `SetDataProvider'
[string "@Blizzard_Communities/GuildNews.lua"]:93: in function `CommunitiesGuildNews_Update'
[string "@Blizzard_Communities/GuildNews.lua"]:62: in function <Blizzard_Communities/GuildNews.lua:57>

Locals:
button = Button {
 0 = <userdata>
 GetData = <function> defined @Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua:106
 index = 2
 Init = <function> defined @Blizzard_Communities/GuildNews.lua:7
 id = 1106
 text = FontString {
 }
 data2 = 0
 newsType = 2
 newsInfo = <table> {
 }
 GetOrderIndex = <function> defined @Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua:124
 header = Texture {
 }
 ElementDataMatches = <function> defined @Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua:119
 dash = FontString {
 }
 SetOrderIndex = <function> defined @Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua:128
 icon = Texture {
 }
 GetElementData = <function> defined @Blizzard_SharedXML/Shared/Scroll/ScrollBoxListView.lua:115
}
news_id = 2
newsInfo = <table> {
 newsType = 2
 guildMembersPresent = 0
 data = <table> {
 }
 whatText = "The Lich King"
 isSticky = true
 isHeader = false
 weekday = 1
 month = 4
 year = 24
 day = 5
 newsDataID = 1106
 whoText = "Tears of the Forgotten"
}
text1 = "Tears of the Forgotten"
text2 = nil
difficulty = 0
displayHeroic = nil
displayMythic = nil
formatString = nil
(*temporary) = <function> defined =[C]:-1
(*temporary) = nil
(*temporary) = <function> defined =[C]:-1
(*temporary) = "attempt to index local 'formatString' (a nil value)"