WowAce

What steps will reproduce the problem?
1.Enter holiday Headless horseman instance
2. error pops up
3.

What is the expected output? What do you see instead?
no error - error

What version of the product are you using?
v4.0.0-beta51-13-gb5456a3

Do you have an error log of what happened?

Message: Interface\AddOns\PitBull4\GroupHeader.lua:1418: Usage: UnitGUID("unit")
Time: 10/19/14 11:39:50
Count: 1
Stack: [C]: in function `UnitGUID'
Interface\AddOns\PitBull4\GroupHeader.lua:1418: in function <Interface\AddOns\PitBull4\GroupHeader.lua:1412>

Locals: (*temporary) = nil

Please provide any additional information below.
This error happened upon entering instance for headless horseman instance

Still getting error in mythic SOO

I have a group made for multiple boss frames (for example protectors has three bosses) and call it boss_party hence the name you see.

Message: Interface\AddOns\PitBull4\GroupHeader.lua:1418: Usage: UnitGUID("unit") Time: 10/21/14 19:55:45 Count: 2 Stack: Interface\AddOns\PitBull4\GroupHeader.lua:1418: in function <Interface\AddOns\PitBull4\GroupHeader.lua:1412>

Locals: self = PitBull4_EnemyGroups_Boss_Party { 0 = <userdata> 2 = PitBull4_EnemyGroups_Boss_PartyUnitButton2 { } ForceUnitFrameCreation = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 3 = PitBull4_EnemyGroups_Boss_PartyUnitButton3 { } 4 = PitBull4_EnemyGroups_Boss_PartyUnitButton4 { } 5 = PitBull4_EnemyGroups_Boss_PartyUnitButton5 { } UnwrapScript = <function> defined @Interface\FrameXML\SecureHandlers.lua:710 IterateMembers = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:1067 ProxySetAttribute = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:146 UnforceShow = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 ApplyConfigModeState = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 is_wacky = false RefreshGroup = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 layout = "Boss_Party" unit_group = "boss" group_based = false ForceShow = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 name = "Boss_Party" group_db = <table> { } Rename = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:1162 RefreshLayout = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 ConfigureChildren = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 Execute = <function> defined @Interface\FrameXML\SecureHandlers.lua:699 Update = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 SetFrameRef = <function> defined @Interface\FrameXML\SecureHandlers.lua:715 RefixSizeAndPosition = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:246 1 = PitBull4_EnemyGroups_Boss_PartyUnitButton1 { } WrapScript = <function> defined @Interface\FrameXML\SecureHandlers.lua:704 super_unit_group = "boss" sort_method = "INDEX" sort_direction = "ASC" show_solo = true include_player = false ClearFrames = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:1195 UpdateMembers = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:140 layout_db = <table> { } UpdateShownState = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 RecheckConfigMode = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:553 GetMaxUnits = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:1019 InitialConfigFunction = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:503 } event = "INSTANCE_ENCOUNTER_ENGAGE_UNIT" arg1 = nil (for generator) = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:993 (for state) = PitBull4_EnemyGroups_Boss_Party { 0 = <userdata> 2 = PitBull4_EnemyGroups_Boss_PartyUnitButton2 { } ForceUnitFrameCreation = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 3 = PitBull4_EnemyGroups_Boss_PartyUnitButton3 { } 4 = PitBull4_EnemyGroups_Boss_PartyUnitButton4 { } 5 = PitBull4_EnemyGroups_Boss_PartyUnitButton5 { } UnwrapScript = <function> defined @Interface\FrameXML\SecureHandlers.lua:710 IterateMembers = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:1067 ProxySetAttribute = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:146 UnforceShow = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 ApplyConfigModeState = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 is_wacky = false RefreshGroup = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 layout = "Boss_Party" unit_group = "boss" group_based = false ForceShow = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 name = "Boss_Party" group_db = <table> { } Rename = <function> defined @Interface\AddOns\PitBull4\GroupHeader.lua:1162 RefreshLayout = <function> defined @Interface\AddOns\PitBull4\Main.lua:452 ConfigureChildren = <function> defined @Interface\AddOns\PitBull4\Main.

I still need to figure out why this is happening, but I committed a fix to stop the error.

@nebula169: Go

Just wanted to follow up on testing this.

I went into throne of the four winds that brings up boss frames on 3 mini bosses. The frames displayed fine and even went away after downing the third mini boss and moving on to the final one. I'll try and get into soo this week (so burnt out of that place) and test it where I first threw the error and see if this patch fixes the issue.