<string>:\"*:OnHide\":7: Proposal not hidden through StaticPopupSpecial.\n<string>:\"*:OnHide\":7: in function <[string \"*:OnHide\"]:1>\n<in C code>: in function `Hide'\nInterface\\FrameXML\\StaticPopup.lua:3513: in function <Interface\\FrameXML\\StaticPopup.lua:3512>:\n<in C code>: in function `StaticPopupSpecial_Hide'\n<string>:\"*:OnClick\":2: in function <[string \"*:OnClick\"]:1>\n\nLocals:|r\nself = LFDDungeonReadyPopup {\n 0 = <userdata>\n dungeonID = 258\n}\nhidingCaller = \"Interface\\FrameXML\\StaticPopup.lua:3513: in function <Interface\\FrameXML\\StaticPopup.lua:3512>\"\n\n

<string>:\"*:OnHide\":7: Proposal not hidden through StaticPopupSpecial.\n<string>:\"*:OnHide\":7: in function <[string \"*:OnHide\"]:1>\n<in C code>: in function `Hide'\nInterface\\FrameXML\\StaticPopup.lua:3513: in function <Interface\\FrameXML\\StaticPopup.lua:3512>:\n<in C code>: in function `StaticPopupSpecial_Hide'\nInterface\\FrameXML\\LFDFrame.lua:55: in function <Interface\\FrameXML\\LFDFrame.lua:41>:\n\nLocals:|r\nself = LFDDungeonReadyPopup {\n 0 = <userdata>\n dungeonID = 258\n}\nhidingCaller = \"Interface\\FrameXML\\StaticPopup.lua:3513: in function <Interface\\FrameXML\\StaticPopup.lua:3512>\"\n\n

local t = {}
t[1] = "foo"
print(t[1]) -- Result: "foo", note that I'm using the index reference for brevity here, a string will provide the exact same results.

t[1] = nil
print(t[1]) -- Result: nil, because the entry was set to nil.
print(t[2]) -- Result: nil, because while the table "t" exists, the subtable [2] does not. I give this example because without knowing the code behind a table's creation, it's very hard to tell this and the previous result apart - You can't expect different results from entries that do exist but are nil, and those that don't.
print(t[2][1]) -- Result: attempt to index field '?' (a nil value) - Except in this case, where the table containing what you're trying to access doesn't exist in the first place.

-- Now for the interesting part.
local foo = nil
if foo then
print("ohaithar")
else
print("No such luck")
end -- Result: "No such luck". A nil local doesn't validate.

t[1] = nil
if t[1] then
print("ohaithar")
else
print("No such luck")
end -- Result: "ohaithar". A nil table entry does, though. Strange, but you get used to it.

StaticPopupDialogs["CONFIRM_LOOT_ROLL"] = nil

StaticPopup_Hide("CONFIRM_DISENCHANT_ROLL");

	if ( event == "CONFIRM_DISENCHANT_ROLL" ) then
		local texture, name, count, quality, bindOnPickUp = GetLootRollItemInfo(arg1);
		local dialog = StaticPopup_Show("CONFIRM_LOOT_ROLL", ITEM_QUALITY_COLORS[quality].hex..name.."|r");
		if ( dialog ) then
			dialog.text:SetFormattedText(LOOT_NO_DROP_DISENCHANT, ITEM_QUALITY_COLORS[quality].hex..name.."|r");
			StaticPopup_Resize(dialog, "CONFIRM_LOOT_ROLL");
			dialog.data = arg1;
			dialog.data2 = arg2;
		end
		return;
	end