WebRequest Exception: "The attempted operation is not supported for the type of object referenced"

microsoft.public.dotnet.framework

23 Aug 2006 11:47 PM

Taylor Brown

We have written an asynchronous download class that uses the WebRequest
to perform downloads. Things are working fine in-house, and it's fine
for the vast majority of our users, but there is an increasingly large
of people who are getting the following exception:

Exception Type: System.Net.Sockets.SocketException
ErrorCode: 10045
SocketErrorCode: OperationNotSupported
NativeErrorCode: 10045
Message: The attempted operation is not supported for the type of
object referenced

Doing a search on that phrase ("The attempted operation is not
supported for the type of object referenced") almost immediately led me
to this page: "How to determine and recover from Winsock2 corruption"
http://support.microsoft.com/kb/811259

Using the instructions on that page has worked for 100% of the users
with the problem! At first I though, "Great!" But now we're seeing a
lot of these, and I'm starting to think that since it's not that
isolated, it might not really be a true "problem" on their machines.
It might be a firewall program or some other incomptaibility. Have
other people seen this before? Do you know of something "innocuous"
that could be causing the SocketException?

Any hints, guesses, or shots in the dark would be greatly appreciated.

Many thanks,

Taylor

30 Aug 2006 3:17 PM

taybro@gmail.com

In case someone else comes across this error and stumbles across this
thread, I have found and fixed it in our app.

I have posted the results of my research and well as the details of my
final workaround here:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=678862&SiteID=1
(Watch for link wraparound)

In case that link dissapears some day, just know this: Be wary of
calling the asynchronous versions of the methods to download files if
you are creating asynchronous threads in your app with the
Delegate.BeginInvoke method. (This includes:
WebClient.DownloadFileAsync and WebRequest.BeginGetResponse)
It will work on most machines, but it won't work on machines that have
"corrupted" winsock settings. I use the term "corrupted" loosely. The
machines that fit this definition were often just machines with foreign
LSPs, and that didn't have any other networking problems.

Cheers,

Taylor

Taylor Brown wrote:
Show quote

> We have written an asynchronous download class that uses the WebRequest
> to perform downloads. Things are working fine in-house, and it's fine
> for the vast majority of our users, but there is an increasingly large
> of people who are getting the following exception:
>
> Exception Type: System.Net.Sockets.SocketException
> ErrorCode: 10045
> SocketErrorCode: OperationNotSupported
> NativeErrorCode: 10045
> Message: The attempted operation is not supported for the type of
> object referenced
>
> Doing a search on that phrase ("The attempted operation is not
> supported for the type of object referenced") almost immediately led me
> to this page: "How to determine and recover from Winsock2 corruption"
> http://support.microsoft.com/kb/811259
>
> Using the instructions on that page has worked for 100% of the users
> with the problem! At first I though, "Great!" But now we're seeing a
> lot of these, and I'm starting to think that since it's not that
> isolated, it might not really be a true "problem" on their machines.
> It might be a firewall program or some other incomptaibility. Have
> other people seen this before? Do you know of something "innocuous"
> that could be causing the SocketException?
>
> Any hints, guesses, or shots in the dark would be greatly appreciated.
>
> Many thanks,
>
> Taylor