Sharepoint 2010, ClientContext & 401 Unauthorized

I am trying to connect to a Sharepoint instance to publish some content using a third-party tool.

I have no control over the Sharepoint instance, but I am sure that my account has full permissions.

        ClientContext ctx = new ClientContext("https://thesharepointsite.com");
        ctx.Credentials = new System.Net.NetworkCredential(@"username", "password", "domain");
        Web w = ctx.Web;
        ctx.Load(w);
        ctx.ExecuteQuery();

In the line ExecuteQuery, I get an exception:

The remote server returned an error: (401) Unauthorized.

(There is no internal exception.)

I can confirm that the URL and credentials work when logging into the browser.

Based on this question , I believe this is a permissions issue.

If so, what permission do I need to request?

Other questions "I tried without success:

401 Error - Sharepoint 2007

SharePoint Server Authentication Failure

401 Unauthorized exception while reading data from a SharePoint 2010 document library

Update

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