Export Sheets to DWG (placeholder sheets issue)

I am not trying to beat a dead horse lol and I know this has been run over and over but I am still having issues. all of my sheets export out with no problem the problem happens when it hits the sheets that are not in the set yet (placeholder sheets) then the script just stops can anyone help me with this one?

here is the error

here is the sheet list with the placeholder sheets

here is the code

# Copyright(c) 2016, Konrad K Sobon
# @arch_laboratory, http://archi-lab.net

# Import Element wrapper extension methods
import clr
import Revit

# Import DocumentManager and TransactionManager
import RevitServices
from RevitServices.Persistence import DocumentManager
doc = DocumentManager.Instance.CurrentDBDocument

# Import RevitAPI
import Autodesk
from Autodesk.Revit.DB import *

import System
from System.Collections.Generic import *

import sys
pyt_path = r'C:\Program Files (x86)\IronPython 2.7\Lib'

#The inputs to this node will be stored as a list in the IN variable.
dataEnteringNode = IN

def ProcessList(_func, _list):
    return map( lambda x: ProcessList(_func, x) if type(x)==list else _func(x), _list )

def ProcessParallelLists(_func, *lists):
	return map( lambda *xs: ProcessParallelLists(_func, *xs) if all(type(x) is list for x in xs) else _func(*xs), *lists )

def Unwrap(item):
	return UnwrapElement(item)

folderPath = IN[0]

if isinstance(IN[1], list):
	views = ProcessList(Unwrap, IN[1])
	views = list(Unwrap(IN[1]))

if isinstance(IN[2], list):
	names = IN[2]
	names = list(IN[2])
dwg_opt = IN[3]

RunIt = IN[5]

def ExportDwg(name, view, folder = folderPath):
	options = None
	settings = FilteredElementCollector(doc).WherePasses(ElementClassFilter(ExportDWGSettings))
	for element in settings:
		if element.Name == dwg_opt:
			options = element.GetDWGExportOptions()
	if options is None:
		options = DWGExportOptions()
	options.MergedViews = IN[4]
	views = List[ElementId]()
	result = doc.Export(folder, name, views, options)
	return result

if RunIt:
		errorReport = None
		# run export
		ProcessParallelLists(ExportDwg, names, views)
		# if error accurs anywhere in the process catch it
		import traceback
		errorReport = traceback.format_exc()
	errorReport = "Please set the RunIt to True!"

#Assign your output to the OUT variable
if errorReport == None:
	OUT = 0
	OUT = errorReport

here is the dynamo file
Export All Plans CAD.dyn (47.7 KB)

Thanks in advance for the help

OK I deleted the placeholder sheets and I was correct the script ran fine. how do I filter out the placeholder sheets?

just found the node sheets.isplaceholder now lets see if I can figure out how to use it to filter out the placeholder sheets

got it thanks to Konrad_K_Sobon old reply