Lua Marry system

[Bug]

My console is getting spammed with this error:

[Error - CreatureScript Interface]
domodlib('marry_func')
function onLook(cid, thing, position, lookDistance)
if isPlayer(thing.uid) and isMarried(thing.uid) then
doPlayerSetSpecialDescription(thing.uid,'.\n'..(getPlayerSex(thing.uid) == 0 and 'She' or 'He')..' is married to '..getPartner(thing.uid))
end
return true
end:onLook
Description:
[string "LuaInterface::loadBuffer"]:4: attempt to concatenate a nil value
stack traceback:
        [string "LuaInterface::loadBuffer"]:4: in function <[string "LuaInterface::loadBuffer"]:2>

The mod is thisone:

<?xml version="1.0" encoding="UTF-8"?>  
<mod name="MarriageSystem" version="1.0" author="Vodkart" contact="xtibia.com" enabled="yes">  
<config name="marry_func"><![CDATA[
 
marry_config = {
OnlyDifferentSex = false,
Marry_Price = 300000,
Divorce_Price = 100000,
Level = 50,
MaxSqm = 7, -- to marry
Text = {'I love you!','My love!','Baby dear!'},
RingID = 10502,
TimeAccept = 60,
storage1 = 300235,
storage2 = 300236,
storage3 = 300237
}
 
function isMarried(cid)
local m = db.getResult("SELECT `player_id` FROM `marriage_system` WHERE `player_id` = '"..getPlayerGUID(cid).."';")
if(m:getID() == -1) then
local e = db.getResult("SELECT `partner` FROM `marriage_system` WHERE `partner` = '"..getPlayerGUID(cid).."';")
if(e:getID() == -1) then
return false
end
end
return true
end
function isPatner(cid)
local p = db.getResult("SELECT `partner` FROM `marriage_system` WHERE `player_id` = '"..getPlayerGUID(cid).."';")
if(p:getID() == -1) then
return true
end
return false
end
function Ponline(player)
local rows = db.getResult("SELECT `online` FROM `players` WHERE `id` = " .. player .. ";")
local on = rows:getDataInt("online")
if on ~= 0 then
return TRUE
else
return FALSE
end
end
function getPartner(cid)
if isPatner(cid) then
a = db.getResult("SELECT `player_id` FROM `marriage_system` WHERE `partner` = '"..getPlayerGUID(cid).."';")
b = "player_id"
else
a = db.getResult("SELECT `partner` FROM `marriage_system` WHERE `player_id` = '"..getPlayerGUID(cid).."';")
b = "partner"
end
local query = a
return getPlayerNameByGUID(query:getDataString(b))
end
function doMarry(cid, patner)
return db.executeQuery("INSERT INTO `marriage_system` (`player_id`, `partner`, `marriage_date`) VALUES ('".. getPlayerGUID(cid) .."', '"..patner.."', '".. os.time() .."');")
end
function doDivorcePlayer(cid)
if isPatner(cid) then
pid,player = getPlayerGUIDByName(getPartner(cid)),getPlayerByNameWildcard(getPartner(cid))
else
pid,player = getPlayerGUID(cid),cid
end
return db.executeQuery("DELETE FROM `marriage_system` WHERE `player_id` = '" .. pid .. "';")
end
function getMarryDate(cid)
local player = isPatner(cid) and getPlayerGUIDByName(getPartner(cid)) or getPlayerGUID(cid)
local date = db.getResult("SELECT `marriage_date` FROM `marriage_system` WHERE `player_id` = '"..player.."';")
return os.date("%d %B %Y %X ", date:getDataInt("marriage_date"))
end
]]></config>
<talkaction words="/marriage;!marriage" event="buffer"><![CDATA[
domodlib('marry_func')
param = string.lower(param)
if (param == "") then
doPlayerSendTextMessage(cid, MESSAGE_STATUS_CONSOLE_BLUE,"invalid command, for more information enter !marriage info")
elseif(param == "info") then
doShowTextDialog(cid,2160,"Marriage Info:\n\nLevel Minimum: "..marry_config.Level.."\nMarriage Cost: "..marry_config.Marry_Price.."\nDivorce Cost: "..marry_config.Divorce_Price.."\n\nMarried Players have a special buffs as a wedding gift given by the union\n\nThis bonus is only given if the married players are nearby.")
elseif(param == "status") then
doPlayerPopupFYI(cid,""..(isMarried(cid) and "Marriage Status".."\n\nMarried with: ["..getPartner(cid).."]\n\nThe date of his marriage was: "..getMarryDate(cid).."" or "you are not married").."")
end
return true
]]></talkaction>
<event type="login" name="MarryRegister" event="script"><![CDATA[
function onLogin(cid)
registerCreatureEvent(cid, "MarryLook")
registerCreatureEvent(cid, "MarryNoAttack")
        return true
        end]]></event>    
<event type="look" name="MarryLook" event="script"><![CDATA[
domodlib('marry_func')
function onLook(cid, thing, position, lookDistance)
if isPlayer(thing.uid) and isMarried(thing.uid) then
doPlayerSetSpecialDescription(thing.uid,'.\n'..(getPlayerSex(thing.uid) == 0 and 'She' or 'He')..' is married to '..getPartner(thing.uid))
end                     
return true
end]]></event>
<event type="combat" name="MarryNoAttack" event="script"><![CDATA[
domodlib('marry_func')
if isPlayer(cid) and isPlayer(target) and isMarried(cid) and isMarried(target) then
if (getCreatureName(target) ==  getPartner(cid))then
doPlayerSendCancel(cid, "You may not attack this player.")
return false
end
end
return true
]]></event>
</mod>

 

[MxSoft]

I have the same issue:
Problem happens when you delete marriage partner from database, so you need to make an script that when a players from marriage_system is not in player table, delete the marriage, on startup would be better.