Lua Error Interface Lua

[Vrotz]

I've this error when a player use destroy field on tile

[Error - Spell Inferface]
data/spells/scripts/support/destroy field rune.lua:onCastSpell
Description:
<LuaDoRemoveItem> Item not Found

My script lua

UNREMOVABLE_FIELDS = {1497, 1498, 1499, 1505, 1506, 1507, 1508, 7465, 7466, 7467, 7468, 7469, 7470, 7471, 7472, 7473, 11094, 11095}

local function doRemoveField(cid, pos)
	local field = getTileItemByType(pos, ITEM_TYPE_MAGICFIELD)
	if(not isInArray(UNREMOVABLE_FIELDS, field.itemid)) then
		doRemoveItem(field.uid)
		doSendMagicEffect(pos, CONST_ME_POFF)
		return true
	end

	doPlayerSendDefaultCancel(cid, RETURNVALUE_NOTPOSSIBLE)
	doSendMagicEffect(getPlayerPosition(cid), CONST_ME_POFF)
	return false
end

function onCastSpell(cid, var)
	local pos = variantToPosition(var)
	if(pos.x == CONTAINER_POSITION) then
		pos = getThingPos(cid)
	end

	if(pos.x ~= 0 and pos.y ~= 0) then
		return doRemoveField(cid, pos)
	end

	doPlayerSendDefaultCancel(cid, RETURNVALUE_NOTPOSSIBLE)
	doSendMagicEffect(getPlayerPosition(cid), CONST_ME_POFF)
	return false
end

How I can fix this?

 

[Limos]

UNREMOVABLE_FIELDS = {1497, 1498, 1499, 1505, 1506, 1507, 1508, 7465, 7466, 7467, 7468, 7469, 7470, 7471, 7472, 7473, 11094, 11095}

local function doRemoveField(cid, pos)
	local field = getTileItemByType(pos, ITEM_TYPE_MAGICFIELD)

	if(field.uid == 0) then
		doPlayerSendDefaultCancel(cid, RETURNVALUE_NOTPOSSIBLE)
		doSendMagicEffect(getPlayerPosition(cid), CONST_ME_POFF)
		return false
	end

	if(not isInArray(UNREMOVABLE_FIELDS, field.itemid)) then
		doRemoveItem(field.uid)
		doSendMagicEffect(pos, CONST_ME_POFF)
		return true
	end

	doPlayerSendDefaultCancel(cid, RETURNVALUE_NOTPOSSIBLE)
	doSendMagicEffect(getPlayerPosition(cid), CONST_ME_POFF)
	return false
end

function onCastSpell(cid, var)
	local pos = variantToPosition(var)
	if(pos.x == CONTAINER_POSITION) then
		pos = getThingPos(cid)
	end

	if(pos.x ~= 0 and pos.y ~= 0) then
		return doRemoveField(cid, pos)
	end

	doPlayerSendDefaultCancel(cid, RETURNVALUE_NOTPOSSIBLE)
	doSendMagicEffect(getPlayerPosition(cid), CONST_ME_POFF)
	return false
end

 

[Vrotz]

Thanks.
REP+.