Bug 30883

Summary: HttpClient will not complete NTLM handshake
Product: iOS Reporter: Matthew Noel <matthew.m.noel>
Component: BCL Class LibrariesAssignee: Bugzilla <bugzilla>
Severity: normal CC: kumpera, masafa, mono-bugs+monotouch
Priority: ---    
Version: XI 8.10   
Target Milestone: Untriaged   
Hardware: Macintosh   
OS: Mac OS   
URL: http://forums.xamarin.com/discussion/42647/problem-with-httpclient-after-updating-xamarin-ios
Tags: Is this bug a regression?: ---
Last known good build:

Description Matthew Noel 2015-06-08 00:47:19 UTC
In 8.10.x the HttpClient component appears to not complete the full NTLM handshake while executing an HttpRequest. The HttpResponse message is 401 Unauthorized, but what should happen is that additional back and forth messages should be sent in the background in order to successfully receive a 200 status code.

The last working version is Making no other change beyond updating to any version of 8.10.x.x will cause the 401 Unauthorized error and the workaround is to downgrade back to

This forum post describes the issue and indicates downgrading to solves the issue for several people:
Comment 1 Marek Safar 2015-06-08 03:54:29 UTC

*** This bug has been marked as a duplicate of bug 30869 ***