vbscript runtime error object variable not set when using object.writeline

I am creating a script to download an update file ([server_path]\local.swf) from a remote server using vbscript. the script will be run through a windows command line and will accept parameters. one of these parameters is the new_hash, it contains the hash of the file to be downloaded. This hash will be used to compare with hash of the file that is already in my pc (c:\mcgfiles\avp\local.swf). If the same, log comments and do nothing. If not then download the local.swf and place it in a temporary folder c:\mcgfiles\avp-temp. Since the vbscript will be accessing an sftp server to dowload the file, I made some delays in the script and check if the file has been downloaded before proceeding to the next step. If the files is already in place, I will create a hash.txt in the same folder c:\mcgfiles\avp-temp, read it then compare to the hash passed through the script. Error occurs when running the script:

vbscript runtime error object variable not set when using object.writeline

here is my script:

Option Explicit
Dim Arg, hostname, new_hash, file_version
Dim obj, objLogActivity, objLogStatus, objLogProgram, objCurrHashFile, shellSFTP, WshShell
Dim tmp, datestamp, datestamp2, logCommand, current_hash, comparison, updateAVP, logfile, commandfile, retryLocalSWF
Dim tokenGenHash, retryHashTXT, tokenReadHash, objDownHashFile, downloaded_hash
Set Arg = WScript.Arguments
hostname = Arg(0)
new_hash = Arg(1)
file_version = Arg(2)
tmp=now()
datestamp = DatePart("yyyy",tmp) & "-" & Right("00" & DatePart("m",tmp),2) & "-" & Right("00" & DatePart("d",tmp),2)
datestamp2 = DatePart("yyyy",tmp)&Right("00" & DatePart("m",tmp),2)&Right("00" & DatePart("d",tmp),2)&Right("00" & DatePart("H",tmp),2)&Right("00" & DatePart("n",tmp),2)&Right("00" & DatePart("s",tmp),2)

Set obj = CreateObject("Scripting.FileSystemObject")
Set objLogActivity = obj.CreateTextFile("C:\mcgfiles\logs\activity\activity_"& hostname &"_"&datestamp&".log")
objLogActivity.Close
Set objLogStatus = obj.CreateTextFile("C:\mcgfiles\logs\status\status_"& hostname &"_"&datestamp&".log")
objLogStatus.Close
If obj.FileExists("C:\mcgfiles\logs\program\program_"&hostname&"_"&datestamp&".log") then
    logCommand = 8
Else
    logCommand = 2
    Set objLogProgram = obj.CreateTextFile("C:\mcgfiles\logs\program\program_"&hostname&"_"&datestamp&".log")
    objLogProgram.Close
End If

Set objLogActivity = obj.OpenTextFile("C:\mcgfiles\logs\activity\activity_"& hostname &"_"&datestamp&".log",2)
Set objLogStatus = obj.OpenTextFile("C:\mcgfiles\logs\status\status_"& hostname &"_"&datestamp&".log",2)
Set objLogProgram = obj.OpenTextFile("C:\mcgfiles\logs\program\program_"&hostname&"_"&datestamp&".log",logCommand)

Set objCurrHashFile = obj.OpenTextFile("C:\mcgfiles\avp\hash.txt",1)
current_hash = objCurrHashFile.ReadLine
objCurrHashFile.Close

comparison = StrComp(new_hash, current_hash)
If comparison = 0 Then
    objLogProgram.WriteLine datestamp2&vbTab&Wscript.ScriptName&vbTab&"INFO"&vbTab&"UPDATE STOPPED. AVP FILE IN LOCAL IS UPDATED."
    objLogProgram.Close
    objLogActivity.Write datestamp2&vbTab&Wscript.ScriptName&vbTab&"INFO"&vbTab&"AVP IN LOCAL IS CURRENTLY UPDATED."
    objLogActivity.Close
    objLogStatus.Write "8"&vbTab&datestamp2
    objLogStatus.Close
    updateAVP = False
Else
    logfile = "c:\mcgfiles\logs\program\updateAVPSFTPLogs_"&datestamp&".log"
    commandfile = "c:\scripts\updateAVPSFTPCommands.txt"
    Set shellSFTP=createobject("wscript.shell")
    shellSFTP.run "cmd /k c:\scripts\psftp -i c:\scripts\rsa_id.ppk [email protected] -be -b "&commandfile&" >"&logfile,0
    Set shellSFTP = Nothing
    updateAVP = True
End If

If updateAVP = True Then
    objLogProgram.WriteLine datestamp2&vbTab&Wscript.ScriptName&vbTab&"INFO"&vbTab&"OPENING SFTP FOR AVP FILE TRANSFER"
    objLogProgram.Close
    retryLocalSWF = 3
    Do While retryLocalSWF > 0
        If obj.FileExists("C:\mcgfiles\avp-temp\local.swf") Then
            tokenGenHash = True 
            retryLocalSWF = retryLocalSWF - 3
        Else
            Wscript.Sleep 10000
            tokenGenHash = False
            retryLocalSWF = retryLocalSWF - 1           
        End If
    Loop
End If
If tokenGenHash = True Then
    objLogProgram.WriteLine datestamp2&vbTab&Wscript.ScriptName&vbTab&"SUCCESS"&vbTab&"AVP SUCCESSFULLY DOWNLOADED. GENERATING HASH FOR VALIDITY"
    objLogProgram.Close
    Set WshShell= Wscript.CreateObject("Wscript.Shell")
    WshShell.Run "C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe $someFilePath = 'C:\mcgfiles\avp-temp\local.swf';$md5 = new-object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider;$md5hash = [System.BitConverter]::ToString($md5.ComputeHash([System.IO.File]::ReadAllBytes($someFilePath)));$newmd5hash = $md5hash -replace '-','';$newmd5hash.ToLower() | Out-File 'C:\mcgfiles\avp-temp\hash.txt' -Encoding Default; return $newmd5hash.ToLower()",0
    retryHashTXT = 0
    Do While retryHashTXT < 3
        If obj.FileExists("C:\mcgfiles\avp-temp\hash.txt") Then
            tokenReadHash = True
            retryHashTXT = retryHashTXT + 3
        Else
            Wscript.Sleep 10000
            tokenReadHash = False
            retryHashTXT = retryHashTXT + 1
        End If
    Loop        
Else
    objLogProgram.WriteLine datestamp2&vbTab&Wscript.ScriptName&vbTab&"ERROR"&vbTab&"AVP WAS NOT TRANSFERRED PROPERLY."
    objLogProgram.Close
    objLogActivity.WriteLine datestamp2&vbTab&Wscript.ScriptName&vbTab&"ERROR"&vbTab&"AVP WAS NOT TRANSFERRED PROPERLY."
    objLogActivity.Close
    objLogStatus.Write "9"&vbTab&datestamp2
    objLogStatus.Close
End If

If tokenReadHash = True Then
    Set objDownHashFile = obj.OpenTextFile("C:\mcgfiles\avp-temp\hash.txt",1)
    downloaded_hash = objDownHashFile.ReadLine
    objDownHashFile.close

End If

Thanks in advance