Critical error ACCESS_VIOLATION in script...

Settings={}
Settings.Name = "test"
local function pdump(tbl)
   local res={} for k,v in pairs(tbl) do res[#res+1]=("%s=%s"):format(k,v) end
   return '{'..table.concat(res,', ')..'}'
end
function Init() return 1 end
function OnCalculate(index)
   if index == 1 then
      message("[Indicator] getParamEx2 'PRICEMAX' " .. pdump(getParamEx2('SPBFUT', 'RIH2', 'PRICEMAX')))
   end
   return nil
end
function OnChangeSettings()
   message("[Indicator] ParamRequest")
   message("[Indicator] ParamRequest ".. tostring(ParamRequest('SPBFUT', 'RIH2', 'PRICEMAX')))
end
function OnDestroy()
   message("[Indicator] CancelParamRequest")
   message("[Indicator] CancelParamRequest ".. tostring(CancelParamRequest('SPBFUT', 'RIH2', 'PRICEMAX')))
end 

local function pdump(tbl)
   local res={} for k,v in pairs(tbl) do res[#res+1]=("%s=%s"):format(k,v) end
   return '{'..table.concat(res,', ')..'}'
end
function main()
   message("[Script] ParamRequest ".. tostring(ParamRequest('SPBFUT', 'RIH2', 'PRICEMAX')))
   message("[Script] getParamEx2 'PRICEMAX' " .. pdump(getParamEx2('SPBFUT', 'RIH2', 'PRICEMAX')))
   message("[Script] CancelParamRequest ".. tostring(CancelParamRequest('SPBFUT', 'RIH2', 'PRICEMAX')))
end