Outlook prompting for SharePoint web server credentials with Shared Events Calendar
We have developed a number of team sites with the Events web part in SharePoint 2007. The team members have connected these calendars to their Outlook (Office 2007) for synchronization and ease of use. I have a few users that have upgraded to Windows 7 and they are now experiencing a prompt for credentials when opening Outlook that references the SharePoint web server (not the SharePoint URL). The prompt is issued by Windows Security and does not have the same dialogue box look-and-feel of a network prompt which leadss me to think this might be related to Windows 7 security. All of the browser options for Trusted sites remain intact and pass through to the SharePoint site directly remains unaffected. My Windows XP users are not experiencing this issue. I have searched all over the web for references to this, but haven't found anything remotely related (read: useful). If anyone else is experiencing this and has determined the cause and fix, I would be most appreciative.
September 5th, 2009 1:29am
Are you using Kerberos authentication? I have seen some articles floating around referencing an issue with Windows 7 / IE8 and Kerberos that sounds similar to this. Apparently, Windows 7 / IE8handles resolving DNS CNAMEs differently and will attempt to authenticate using the underlying server nameinstead of the FQDN. I haven't beenin a position to test the workarounds, but they range from: Rolling back to IE8 Beta (probably not the best option), or... Running SetSPN on the services again using the underlying server names, or... Setting up the DNS entry as an 'Alias' instead of a'Host' entry. I haven't found a concensus on the best resolution, but here's a couple of articles that I ran across that reference this issue:http://social.technet.microsoft.com/Forums/en-US/w7itpronetworking/thread/f649df36-a61b-4d23-a0c6-818dc2eff923http://developers.de/blogs/damir_dobric/archive/2009/08/16/configuring-and-troubleshooting-ntlm-and-kerberos-on-windows-7-windows-server-2008-and-iis7.aspxJason Barron Blog: http://rdacollab.blogspot.com/ CodePlex: http://rdacollaboration.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=28073
September 5th, 2009 6:15pm
This is not a customization (SharePoint Designer related) issue, moved to general.-lambertSincerely, Lambert Qin | Microsoft TechNet Managed Forum Support Posting is provided "AS IS" with no warranties, and confers no rights.
September 7th, 2009 4:10am
Thanks for the feedback, Jason. Oddly enough, directly accessing the SharePoint site that contains the aforementioned Events web part through IE8 on Windows 7 passes through without trouble. We are using Kerberos authentication but without issue in this sense. The trouble only exists once the user Connects to Outlook through ther Actions menu on the web part and adds the calendar to Outlook. Then it asks for authentication every time Outlook is opened. I have a feeling that your insight above is on the right track and I will investigate in that direction a bit further.
September 7th, 2009 5:19am
Was any solution found? I have the same issue withNTLM.
October 1st, 2009 4:08pm
Was any solution found? I have the same issue with NTLM. Turned out to be Alernate Access Mapping issue.
June 8th, 2010 10:29pm
We had a similar issue with Outlook subscriptions to SharePoint calendars. Users had subscribed to calendars on sharepoint site http://sitename. This worked for some time, but all around the same time, users began getting prompted to log in by Outloook whenever it attempted to refresh the calendar. It would not remember credentials. After some digging, it appears that Outlook first attmpts to resolve the long name, even if the user added the subscription using the short name. We had recently extended the sharepoint site to http://sitename.company.com for other reasons, and so Outlook attempted to use that site instead. Because the long name was not in users' intranet zone, they got prompted to log in. Closing Outlook, adding http://sitename.company.com to the intranet zone in IE, and reopening outlook fixed the problem. It could also be a kerberos issue in some cases, but in our case, we verified that Kerberos was working correctly for both names.
May 2nd, 2011 10:48am