Good ol' "attempt to index field '?' (a nil value)" error

[Senuska]

I am trying to revive an old addon called AltaVoice. And of course i am having trouble. the stated error occurs every time i go to the config menu. Also the sliders on the config frame do not show up.

Here is the segment that seems to be causing the trouble (lines 89-101):

function AltaVoice_JoinVoiceChannel()
	local player = UnitName("player");
	local realm = GetRealmName();
	AltaVoice_PlayerOfRealm = player.." of "..realm;	
	local _, isActive = JoinChannelByName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	if (isActive == nil)then
		JoinChannelByName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
		RemoveChatWindowChannel(DEFAULT_CHAT_FRAME:GetID(), AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
		AltaVoice_ChannelName = GetChannelName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	end
	AltaVoice_ChannelName = GetChannelName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	AltaVoice_JoinMasterChannel();
end

The error occurs on line 94:

local _, isActive = JoinChannelByName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);

And here is the rest of the addon for reference:

BINDING_HEADER_ALTAVOICE = "AltaVoice";
BINDING_NAME_PUSHTOTALK = "Push To Talk";

-- Default Variables
AltaVoice_SVars = {};
AltaVoice_TalkTable = {};
AltaVoice_ActiveChannels = {};
AltaVoice_VolumeDipped = false;

function AltaVoice_OnLoad()
	this:RegisterEvent("ADDON_LOADED");
		arg1 = AltaVoice;
	this:RegisterEvent("CHAT_MSG_CHANNEL");
	UIErrorsFrame:AddMessage("AltaVoiceLoaded", 0, 1.0, 0, 1.0, UIERRORS_HOLD_TIME);
	DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : AltaVoice Loaded", 0.0, 1.0, 0.0);
	AltaVoice_Language = this.language;
	SlashCmdList["AltaVoice"] = function(msg)
		AltaVoice_SlashHandler(msg);
	end
	SLASH_AltaVoice1 = "/altavoice";
end

function AltaVoice_SlashHandler(msg)
	if (msg == "")then
		DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : Slash Command List :", 0.0, 1.0, 0.0);
		DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : /altavoice show", 0.0, 1.0, 0.0);
		DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : /altavoice hide", 0.0, 1.0, 0.0);
	end
	
	if (msg == "show")then
		AltaVoice_VoiceWindowTitle:Show();
	end
	
	if (msg == "hide")then
		AltaVoice_VoiceWindowTitle:Hide();
		AltaVoice_Menu_Title:Hide();
	end
end

function AltaVoice_LoadProfile()
	local player = UnitName("player");
	local realm = GetCVar("realmName");
	AltaVoice_PlayerOfRealm = player.." of "..realm;
	if (AltaVoice_SVars[AltaVoice_PlayerOfRealm])then
		AltaVoice_RefreshVisuals();
		DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : Loaded Profile for "..AltaVoice_PlayerOfRealm..".", 0.0, 1.0, 0.0);
	else
		AltaVoice_SVars[AltaVoice_PlayerOfRealm] = {};
		if (IsInGuild())then
			local guildName = GetGuildInfo("player");
			local findSpaces = string.find(guildName, " ");
			if (findSpaces)then
				local starts, ends, cursor = 0,0,1;
				local repairedName = "";
				while (starts ~=nil)do
					starts, ends = string.find(guildName, " ", cursor);
					if (starts ~=nil)then
						repairedName = repairedName..string.sub(guildName, cursor, starts-1);
						cursor = ends +1;
					else
						repairedName = repairedName..string.sub(guildName, cursor);
					end
				end
				guildName = repairedName;
			end
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel = "AltaVoice"..guildName;
		else
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel = "AltaVoice"..player;
		end
		AltaVoice_SVars[AltaVoice_PlayerOfRealm].SpeakListLength = 40;
		AltaVoice_SVars[AltaVoice_PlayerOfRealm].ListMode = "List";
		AltaVoice_SVars[AltaVoice_PlayerOfRealm].AllowInvites = true;
		AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDip = false;
		AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues = {};
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Master = GetCVar("MasterVolume");
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Sound = GetCVar("SoundVolume");
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Music = GetCVar("MusicVolume");
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Ambience = GetCVar("AmbienceVolume");
		AltaVoice_SVars[AltaVoice_PlayerOfRealm].Appearance = {};
			AltaVoice_SVars[AltaVoice_PlayerOfRealm].Appearance.TalkWindow = {};
				AltaVoice_SVars[AltaVoice_PlayerOfRealm].Appearance.TalkWindow.Width = 100;
				AltaVoice_SVars[AltaVoice_PlayerOfRealm].Appearance.TalkWindow.Scale = 1;
			
			
		DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : Profile Created for "..AltaVoice_PlayerOfRealm..".", 0.0, 1.0, 0.0);
	end
end

function AltaVoice_JoinVoiceChannel()
	local player = UnitName("player");
	local realm = GetRealmName();
	AltaVoice_PlayerOfRealm = player.." of "..realm;	
	local _, isActive = JoinChannelByName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	if (isActive == nil)then
		JoinChannelByName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
		RemoveChatWindowChannel(DEFAULT_CHAT_FRAME:GetID(), AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
		AltaVoice_ChannelName = GetChannelName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	end
	AltaVoice_ChannelName = GetChannelName(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	AltaVoice_JoinMasterChannel();
end

function AltaVoice_JoinVoiceChannelOnClick()
	local channelName = "AltaVoice"..AltaVoice_Menu_Panel_ChannelName:GetText();
	local findSpaces = string.find(channelName, " ");
	if (findSpaces)then
		local starts, ends, cursor = 0,0,1;
		local repairedName = "";
		while (starts ~=nil)do
			starts, ends = string.find(channelName, " ", cursor);
			if (starts ~=nil)then
				repairedName = repairedName..string.sub(channelName, cursor, starts-1);
				cursor = ends +1;
			else
				repairedName = repairedName..string.sub(channelName, cursor);
			end
		end
		channelName = repairedName;
		AltaVoice_Menu_Panel_ChannelName:SetText(repairedName);
	end
	AltaVoice_Menu_Panel_ChannelName:ClearFocus();
	ChatFrame1.editBox:SetText("/leave "..AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel);
	ChatEdit_SendText(ChatFrame1.editBox);
	AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel = channelName;
	AltaVoice_JoinVoiceChannel();
	AltaVoice_TalkTable = {};
	AltaVoice_UpdateTalkList();
end

function AltaVoice_JoinMasterChannel()
	local _, isActive = JoinChannelByName("AltaVoiceMaster");
	if (isActive == nil)then
		JoinChannelByName("AltaVoiceMaster");
		RemoveChatWindowChannel(DEFAULT_CHAT_FRAME:GetID(), "AltaVoiceMaster");
	end
	AltaVoice_MasterChannelID = GetChannelName("AltaVoiceMaster");
end

function AltaVoice_StartTalk()
	if (AltaVoice_ChannelName == nil)then
		AltaVoice_JoinVoiceChannel();
	end
	SendChatMessage("StartTalk", "CHANNEL", AltaVoice_Language, AltaVoice_ChannelName);
end

function AltaVoice_StopTalk()
	SendChatMessage("StopTalk", "CHANNEL", AltaVoice_Language, AltaVoice_ChannelName);
end

function AltaVoice_OnEvent()
	if (event == "CHAT_MSG_CHANNEL") then
		if (AltaVoice_ChannelName == nil)then
			AltaVoice_JoinVoiceChannel();
		end
		local player = arg2;
		local fromChannel = arg4;
		local monitorChannel = AltaVoice_ChannelName..". "..AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel;
		local masterChannel = AltaVoice_MasterChannelID..". AltaVoiceMaster";
		if (fromChannel == monitorChannel)then
			if (arg1 == "StartTalk")then
				AltaVoice_EditTalkTable(player, "talk");
				if (AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDip)then
					AltaVoice_DipVolume();
				end
			end
			if (arg1 == "StopTalk")then
				AltaVoice_EditTalkTable(player, "silent");
			end
		end
		if (fromChannel == masterChannel)then
			local msg = arg1;
			local command = string.sub(msg,1,3);
			local starts, ends = string.find(msg, " ", 5);
			local property1 = string.sub(msg, 5, starts-1);
			local property2 = string.sub(msg, ends+1);
			-- recieve invite request
			if ((command == "inv") and (property1 == UnitName("player")))then
				AltaVoice_InviteRequestFrom = player;
				AltaVoice_InviteRequestChannel = property2;
				AltaVoice_InviteRequested(player, property2);
			end
			-- recieve invite response - Not Accepting
			if ((command == "inr") and (property1 == UnitName("player")) and (property2 == "NA"))then
				DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : "..player.." is not accepting invites at this time.", 1.0, 0.0, 0.0);
			end
			-- recieve invite response - Declined
			if ((command == "inr") and (property1 == UnitName("player")) and (property2 == "DE"))then
				DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : "..player.." declined your invitation.", 1.0, 0.0, 0.0);
			end
			-- recieve invite response - Already Joined
			if ((command == "inr") and (property1 == UnitName("player")) and (property2 == "AJ"))then
				DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : "..player.." is already joined to this channel.", 1.0, 0.0, 0.0);
			end
			-- recieve invite response - Accepted
			if ((command == "inr") and (property1 == UnitName("player")) and (property2 == "AC"))then
				DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : "..player.." accepted your invitation.", 0.0, 1.0, 0.0);
			end
		end
	end
	if (event == "VARIABLES_LOADED")then
		AltaVoice_LoadProfile();
	end
end

function AltaVoice_EditTalkTable(player, command)
	local findloop = 1;
	local find = AltaVoice_TalkTable[findloop];
	local found = nil
	while ((find) and (findloop <= AltaVoice_SpeakListLength))do
		local find = AltaVoice_TalkTable[findloop];
			if (find == player)then
				found = findloop;
			end
		findloop = findloop +1;
	end
	if (command == "talk")then
		if (AltaVoice_TalkTable[player])then
			AltaVoice_TalkTable[player].talk = "talk";
		else
			AltaVoice_TalkTable[player] = {talk = "talk", name = player};
		end
	end
	if (command == "silent")then
		if (AltaVoice_TalkTable[player])then
			AltaVoice_TalkTable[player].talk = "silent";
		end
	end
	AltaVoice_UpdateTalkList();
end

function AltaVoice_UpdateTalkList()
	local onTalkLoop = 1;
	local listLoop = 1;
	local noOneTalking = true;
	for i,v in ipairs(AltaVoice_TalkTable) do
		local getName = AltaVoice_TalkTable[i].name;
		local talking = AltaVoice_TalkTable[i].talk;
		if ((AltaVoice_SVars[AltaVoice_PlayerOfRealm].ListMode == "OnTalk") and (talking == "talk"))then
			getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..onTalkLoop.."_Name"):SetText(getName);
			getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..onTalkLoop):Show();
			getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..onTalkLoop.."_SpeakTexture"):Show();
			noOneTalking = false;
			onTalkLoop = onTalkLoop + 1;
		end
		if (AltaVoice_SVars[AltaVoice_PlayerOfRealm].ListMode == "List")then
			if (talking == "talk")then
				getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop.."_Name"):SetText(getName);
				getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop):Show();
				getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop.."_SpeakTexture"):Show();
				noOneTalking = false;
			end
			if (talking == "silent")then
				getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop.."_Name"):SetText(getName);
				getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop):Show();
				getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop.."_SpeakTexture"):Hide();
			end
			listLoop = listLoop +1;
		end
	end
	if (noOneTalking)then
		AltaVoice_ResetVolume();
	end
	if (AltaVoice_SVars[AltaVoice_PlayerOfRealm].ListMode == "OnTalk")then
		while (onTalkLoop <= AltaVoice_SVars[AltaVoice_PlayerOfRealm].SpeakListLength)do
			getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..onTalkLoop):Hide();
			onTalkLoop = onTalkLoop +1;
		end
	end
	if (AltaVoice_SVars[AltaVoice_PlayerOfRealm].ListMode == "List")then
		while (listLoop <= AltaVoice_SVars[AltaVoice_PlayerOfRealm].SpeakListLength)do
			getglobal("AltaVoice_VoiceWindowTitle_UserSpeaking_"..listLoop):Hide();
			listLoop = listLoop +1;
		end
	end
end

function AltaVoice_InvitePlayer()
	local playerToInvite = AltaVoice_Menu_Panel_InvitePlayerFrame_PlayerToInvite:GetText();
	if ((playerToInvite)and(AltaVoice_MasterChannelID))then
		SendChatMessage("inv "..playerToInvite.." "..AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel, "CHANNEL", AltaVoice_Language, AltaVoice_MasterChannelID);
		DEFAULT_CHAT_FRAME:AddMessage("AltaVoice : Inviting "..playerToInvite.." to join this channel.", 0.0, 1.0, 0.0);
	end
end

function AltaVoice_InviteRequested(from, channel)
	if (AltaVoice_SVars[AltaVoice_PlayerOfRealm].AllowInvites)then
		if (channel == AltaVoice_SVars[AltaVoice_PlayerOfRealm].Monitor_Channel)then
			SendChatMessage("inr "..from.." AJ", "CHANNEL", AltaVoice_Language, AltaVoice_MasterChannelID);
		else
			AltaVoice_InviteRequestWindow_Text:SetText(from.." is inviting you to join "..channel);
			AltaVoice_InviteRequestWindow:Show();
		end
	else
		SendChatMessage("inr "..from.." NA", "CHANNEL", AltaVoice_Language, AltaVoice_MasterChannelID);
	end
end

function AltaVoice_DipVolume()
	if (AltaVoice_VolumeDipped == false)then
		AltaVoice_Volume = {};
		AltaVoice_Volume.Master = GetCVar("MasterVolume");
		AltaVoice_Volume.Sound = GetCVar("SoundVolume");
		AltaVoice_Volume.Music = GetCVar("MusicVolume");
		AltaVoice_Volume.Ambience = GetCVar("AmbienceVolume");
		SetCVar("MasterVolume", AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Master);
		SetCVar("SoundVolume", AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Sound);
		SetCVar("MusicVolume", AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Music);
		SetCVar("AmbienceVolume", AltaVoice_SVars[AltaVoice_PlayerOfRealm].VolumeDipValues.Ambience);
		AltaVoice_VolumeDipped = true;
	end
end

function AltaVoice_ResetVolume()
	if (AltaVoice_VolumeDipped)then
		SetCVar("MasterVolume", AltaVoice_Volume.Master);
		SetCVar("SoundVolume", AltaVoice_Volume.Sound);
		SetCVar("MusicVolume", AltaVoice_Volume.Music);
		SetCVar("AmbienceVolume", AltaVoice_Volume.Ambience);
		AltaVoice_VolumeDipped = false;
	end
end

function AltaVoice_RefreshVisuals()
	AltaVoice_VoiceWindowTitle:SetWidth(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Appearance.TalkWindow.Width);
	AltaVoice_VoiceWindowTitle:SetScale(AltaVoice_SVars[AltaVoice_PlayerOfRealm].Appearance.TalkWindow.Scale);
	AltaVoice_VoiceWindowTitle:SetPoint("TOPLEFT", "AltaVoice_VoiceWindowTitleScaler", "TOPLEFT", 0 ,0);
end

To answer some questions that were asked in another forum AltaVoice_SVars is one of the default variables; its an empty table. And i am guessing from looking at the code that AltaVoice_PlayerOfRealm is being added to the table in order to be saved between sessions. What i don't understand is why it seems to think that either the local variable player or realm is nil. Please, i could really use some help on this!