SSIS Package Out Of Memory Exception

I have an SSIS Package that loads data from a log file. Prior to loading the data I need to prepare the file. I run a script that cleans the file. Then I import the flat file into SQL Server.

Log File Management Task
1. Run Unix Log File Task
2. Import the new log file (flat file) into SQL Server

Error
i.Unix.dtsx
Message: The script threw an exception: Exception of type 'System.OutOfMemoryException' was thrown.

Is this because the system is running out of memory? The RAM on the server is 4gb. Below is a sample of the script. The job doesn't always fail; there are times when the job executes with success and other times when it fails.

Script Source Code
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' Microsoft SQL Server Integration Services Script Task
' Write scripts using Microsoft Visual Basic
' The ScriptMain class is the entry point of the Script Task.
Imports System
Imports System.Data
Imports System.Math
Imports Microsoft.SqlServer.Dts.Runtime
Imports System.Collections.Generic
Imports System.IO
Imports System.Text
Imports System.Diagnostics
Imports System.Globalization
Imports Microsoft.VisualBasic
Imports System.Text.RegularExpressions
Public Class ScriptMain
'********** Begin Error Log Settings **********
'Dim sSource As String = "i.SSIS.Unix.FileManager"
'Dim sLog As String = "Application"
'Dim sMachine As String = "."
'Dim ELog As New EventLog(sLog, sMachine, sSource)
'********** End Error Log Settings **********

Public Sub Main()
'variables for the unix log file
Dim newFile As String = "D:iLogunixlog.txt"
Dim copyFile As String = "\server16iLogunixlog.txt"
'variables for working log files
Dim oldFile As String = "D:i empunixlog.txt"
Dim difFile As String = "D:i empunixdiff.txt"
Dim trimdiff As String = "D:i empunixdifft.txt"
Dim formatTemp As String = "D:i empunixlog_formatted.txt"
Dim errorFile As String = "D:i empunixlog_bad.txt"

'delete unixlog.txt copy unixlog.txt
'if the file is on the local server delete it and copy the new file over
'if the file is not present copy the new file over
Try
If File.Exists(newFile) Then
File.Delete(newFile)
File.Copy(copyFile, newFile)
Else
File.Copy(copyFile, newFile)
End If
While Not File.Exists(newFile)
System.Threading.Thread.Sleep(1000)
End While
'ELog.WriteEntry("FileCopy.Success".ToString(), EventLogEntryType.SuccessAudit, 4, CType(4, Short))
Catch ex As Exception
'ELog.WriteEntry("FileCopy.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 2, CType(4, Short))
End Try

'open the old file; read backwards until we reach the carriage
'return and store that "seek" position; now open the new file and
'seek to that stored position. finally, read the rest of the file
'and write that data to the difference file.
' determine position of last line in the old file
Dim lastLine As Long = GetLastLinePosition(oldFile)
' get all data in new file starting at position determined above
Dim fi As New FileInfo(newFile)
Dim buffer(fi.Length - lastLine) As Byte
Dim fs As New FileStream(newFile, FileMode.Open)
Try
fs.Seek(lastLine, SeekOrigin.Begin)
fs.Read(buffer, 0, buffer.Length)
fs.Close()
' write that new data to the difference file
fs = New FileStream(difFile, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None)
fs.Write(buffer, 0, buffer.Length)
fs.Close()
'ELog.WriteEntry("FileCopy.Success".ToString(), EventLogEntryType.SuccessAudit, 4, CType(4, Short))
Catch ex As Exception
'ELog.WriteEntry("FileCopy.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 2, CType(4, Short))
End Try

'remove the partial row from the difference file
Try
TrimFinal(difFile, trimdiff)
'ELog.WriteEntry("TrimFinal.Call.Success".ToString(), EventLogEntryType.SuccessAudit, 4, CType(4, Short))
Catch ex As Exception
'ELog.WriteEntry("TrimFinal.Call.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 2, CType(4, Short))
End Try
'perform the file formatting
sFormatFile(trimdiff, formatTemp, errorFile)
'
Dts.TaskResult = Dts.Results.Success
End Sub

Function GetLastLinePosition(ByVal fileName As String) As Long
Dim pos As Long = -1
Dim fs As New FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
Try
fs.Seek(-2, SeekOrigin.End) ' -2 to skip a potential vbcrlf at the end of file
While fs.Position > 0
fs.Seek(-1, SeekOrigin.Current)
If fs.ReadByte = 10 Then
pos = fs.Position
Exit While
Else
fs.Seek(-1, SeekOrigin.Current)
End If
End While
fs.Close()
'ELog.WriteEntry("GetLastLinePosition.Success".ToString(), EventLogEntryType.SuccessAudit, 4, CType(4, Short))
Catch ex As Exception
'ELog.WriteEntry("GetLastLinePosition.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 2, CType(4, Short))
End Try
Return pos
End Function

Sub TrimFinal(ByVal difFile As String, ByVal trimdiff As String)
Dim fi2 As New FileStream(difFile, FileMode.OpenOrCreate, FileAccess.Read)
Dim fo2 As New FileStream(trimdiff, FileMode.OpenOrCreate, FileAccess.Write)
Dim sr2 As New StreamReader(fi2)
Dim sw2 As New StreamWriter(fo2)
Dim line2 As String
Try
Do While sr2.Peek <> -1
line2 = sr2.ReadLine()
If (sr2.Peek <> -1) Then
sw2.WriteLine(line2)
End If
Loop
sw2.Flush() : sw2.Close()
sr2.Close()
fi2.Close() : fo2.Close()
'ELog.WriteEntry("TrimFinal.Success".ToString(), EventLogEntryType.SuccessAudit, 4, CType(4, Short))
Catch ex As Exception
'ELog.WriteEntry("TrimFinal.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 2, CType(4, Short))
End Try
End Sub

Sub sFormatFile(ByVal currentFile As String, ByVal tempFile As String, ByVal errorFile As String)
Dim tfp As New Microsoft.VisualBasic.FileIO.TextFieldParser(currentFile)
Dim sw As New System.IO.StreamWriter(tempFile)
Dim swErrorFile As New System.IO.StreamWriter(errorFile)
tfp.TextFieldType = FileIO.FieldType.Delimited
tfp.SetDelimiters(",")
tfp.HasFieldsEnclosedInQuotes = True
tfp.TrimWhiteSpace = True
Dim fields() As String
Try
While Not tfp.EndOfData
Try
fields = tfp.ReadFields()
If fields.Length <> 23 Then
'write bad rows to error-file
swErrorFile.WriteLine(String.Join(",", fields))
Else
If fields(3) = "" And fields(13) = "" Then
sw.WriteLine(Chr(34) & String.Join(Chr(34) & "," & Chr(34), fields) & Chr(34))
ElseIf IsDate(fields(3)) = True OrElse fields(3) = Format(CDate(fields(3)), "yyyy-MM-dd HH:mms") And fields(13) = "" Then
sw.WriteLine(Chr(34) & String.Join(Chr(34) & "," & Chr(34), fields) & Chr(34))
ElseIf IsDate(fields(13)) = True OrElse fields(13) = Format(CDate(fields(13)), "yyyy-MM-dd HH:mms") And fields(3) = "" Then
sw.WriteLine(Chr(34) & String.Join(Chr(34) & "," & Chr(34), fields) & Chr(34))
ElseIf IsDate(fields(3)) = True OrElse fields(3) = Format(CDate(fields(3)), "yyyy-MM-dd HH:mms") _
And IsDate(fields(13)) = True OrElse fields(13) = Format(CDate(fields(13)), "yyyy-MM-dd HH:mms") Then
sw.WriteLine(Chr(34) & String.Join(Chr(34) & "," & Chr(34), fields) & Chr(34))
Else
swErrorFile.WriteLine(String.Join(",", fields))
End If
End If
Catch ex As Exception
'ELog.WriteEntry("sFormatFile.TFP.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 0, CType(4, Short))
End Try
End While
tfp.Close()
sw.Close()
swErrorFile.Close()
File.Delete(currentFile)
File.Move(tempFile, currentFile)
'ELog.WriteEntry("sFormatFile.Success".ToString(), EventLogEntryType.SuccessAudit, 0, CType(4, Short))
Catch ex As Exception
'ELog.WriteEntry("sFormatFile.Failure" & ControlChars.CrLf & ex.ToString(), EventLogEntryType.Error, 0, CType(4, Short))
Finally
GC.Collect()
End Try
End Sub
End Class
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Does my script seem okay for releasing the server memory usage?

Thanks.