WoWInterface - Issue with Addon on TBC Classic

Firstly, this issue is neither present on the current WoW Classic, or Retail clients, I'm not sure if it's something related to restrictions Blizzard has placed on addons for the TBC beta, or if it's going to be an issue in TBC Classic itself, so..

Code:

Message: Interface\FrameXML\RestrictedExecution.lua:473: Cannot call restricted closure from insecure code

Time: Sun Apr 11 15:33:04 2021

Count: 1

Stack: Interface\FrameXML\RestrictedExecution.lua:473: Cannot call restricted closure from insecure code

[string "=[C]"]: ?

[string "@Interface\FrameXML\RestrictedExecution.lua"]:473: in function <Interface\FrameXML\RestrictedExecution.lua:447>

[string "@Interface\FrameXML\SecureGroupHeaders.lua"]:116: in function <Interface\FrameXML\SecureGroupHeaders.lua:110>

[string "@Interface\FrameXML\SecureGroupHeaders.lua"]:166: in function <Interface\FrameXML\SecureGroupHeaders.lua:123>

[string "@Interface\FrameXML\SecureGroupHeaders.lua"]:399: in function <Interface\FrameXML\SecureGroupHeaders.lua:387>

[string "=[C]"]: in function `Show'

[string "@Interface\FrameXML\SecureStateDriver.lua"]:100: in function <Interface\FrameXML\SecureStateDriver.lua:95>

[string "@Interface\FrameXML\SecureStateDriver.lua"]:164: in function <Interface\FrameXML\SecureStateDriver.lua:146>

[string "=[C]"]: in function `SetAttribute'

[string "@Interface\FrameXML\SecureStateDriver.lua"]:11: in function `RegisterAttributeDriver'

[string "@Interface\AddOns\Roth_UI\embeds\oUF\ouf.lua"]:575: in function `SpawnHeader'

[string "@Interface\AddOns\Roth_UI\units\party.lua"]:258: in main chunk



Locals: (*temporary) = "Cannot call restricted closure from insecure code"

Here's the SpawnHeader method causing the error in oUF:

Lua Code:

function oUF:SpawnHeader(overrideName, template, visibility, ...)
        if(not style) then return error("Unable to create frame. No styles have been registered.") end
 
        template = (template or 'SecureGroupHeaderTemplate')
 
        local isPetHeader = template:match'PetHeader'
        local name = overrideName or generateName(nil, ...)
        local header = CreateFrame('Frame', name, oUF_PetBattleFrameHider, template)
 
        header:SetAttribute("template", "oUF_ClickCastUnitTemplate")
        for i=1, select("#", ...), 2 do
            local att, val = select(i, ...)
            if(not att) then break end
            header:SetAttribute(att, val)
        end
 
        header.style = style
        header.styleFunction = styleProxy
 
        -- Expose the header through oUF.headers.
        table.insert(headers, header)
 
        -- We set it here so layouts can't directly override it.
        header:SetAttribute('initialConfigFunction', initialConfigFunction)
        header:SetAttribute('oUF-headerType', isPetHeader and 'pet' or 'group')
 
        if(Clique) then
            SecureHandlerSetFrameRef(header, 'clickcast_header', Clique.header)
        end
 
        if(header:GetAttribute'showParty') then
            self:DisableBlizzard'party'
        end
 
        if(visibility) then
            local type, list = string.split(' ', visibility, 2)
            if(list and type == 'custom') then
                RegisterAttributeDriver(header, 'state-visibility', list)
            else
                local condition = getCondition(string.split(',', visibility))
                RegisterAttributeDriver(header, 'state-visibility', condition)
            end
        end
 
        return header
    end

And here is where that method is called:

Lua Code:

local party = oUF:SpawnHeader(
      "Roth_UIPartyHeader",
      nil,
      attr.visibility,
      "showPlayer",         attr.showPlayer,
      "showSolo",           attr.showSolo,
      "showParty",          attr.showParty,
      "showRaid",           attr.showRaid,
      "point",              attr.VerticalPoint,
      "yoffset",            attr.yoffset,
      "oUF-initialConfigFunction", ([[
        self:SetWidth(%d)
        self:SetHeight(%d)
        self:SetScale(%f)
      ]]):format(cfg.units.party.vertwidth, cfg.units.party.vertheight, cfg.units.party.scale)
    )
    party:SetPoint("TOPLEFT",partyDragFrame,0,0)

I don't see anything wrong with these, and as stated, they do not cause this exception on WoW Classic or Retail Shadowlands, only on the TBC Classic beta.