Error updating POP up window

[Playfair1965]

here is the info from the error pop up window

1.1.3 Unknown Thread Error: mscorlib
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.ReadCore(Byte[] buffer, Int32 offset, Int32 count)
at System.IO.FileStream.Read(Byte[] array, Int32 offset, Int32 count)
at System.Security.Cryptography.HashAlgorithm.ComputeHash(Stream inputStream)
at EQ2MAPUpdater.MainWindow.GetFileMD5(String strFilePath)
at EQ2MAPUpdater.MainWindow.DownloadUpdates()
at EQ2MAPUpdater.MainWindow.GetUpdates()
at EQ2MAPUpdater.MainWindow.Timer3_Tick(Object sender, EventArgs e)
at System.Windows.Forms.Timer.OnTick(EventArgs e)
at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)Data error (cyclic redundancy check).