C#

Byte[] received = new Byte[256];
int bytesReceived = server1Tcp.Receive(input, input.Length, 0);
dataReceived = System.Text.Encoding.ASCII.GetString(input);

RegistryKey
regKey = Registry.LocalMachine
regkey = regKey.OpenSubKey("Software");
regkey = regKey.OpenSubKey("Adobe");
regKey = regKey.OpenSubKey("Adobe Reader"); /* this line returns a null exception, if this line is commented out I get the expected results on the Adobe Key */

RegistrySecurity = regKey.GetAccessControl();

string fileName;

public void checkUpdates()
{
	foreach (Uri uri in uriList)
	{
		fileName = uri.AbsolutePath.Remove(0, 1);

		if (!File.Exists(fileName))
		{
			doUpdates(true, uri);
			wasUpdated = true;
			continue;
			//'  There's more in the foreach but I don't think it's relevant
		}
	}
}
public void doUpdates(bool checkUpdates, Uri uri)
{
	WebClient client = new WebClient();
	client.DownloadFileCompleted += new AsyncCompletedEventHandler(client_updateFinished);

	//'  We found updates so download the new files.
	if (checkUpdates)
		client.DownloadFileAsync(uri, fileName);
}

private void client_updateFinished(object sender, AsyncCompletedEventArgs e)
{
	if (File.Exists(fileName))
	{
		//*  Here is where I crash, Error quoted below
		xmlDoc.Load(fileName);
	}
}