There are a couple of possible explanations for this.
When a patch comes out, many customers are trying to download the patch at once, which will "clog" the patching client. Please keep trying to update your client, as you will eventually get through. In addition, this is also a known problem with parental controls set within AOL. To allow the client updater proper access to your machine, you must be logged in with the "general access" account within AOL. Any parental controlled account will result in a "201" error.