“No valid proxy can be found” when publishing content type in SharePoint 2010

I found a number of posts with possible fixes for this problem, many of them relating to the Content Type hub URL in the Managed Metadata Service    e.g.

http://social.technet.microsoft.com/Forums/en/sharepoint2010setup/thread/d9efe46c-7d55-4f51-9e09-c41ff4d40bda

http://charliedigital.com/2010/01/06/sharepoint-2010-content-type-publishing-setup/

However, I received this error and the Content Type Hub url in the Managed Metadata Service appeared to be fine. It turned out that a new host header for the content type hub site had been created in IIS and an alternate access mapping added in SharePoint. If I accessed the content type hub site using the original host header (this was the one specified as the Content Type Hub in the managed Metadata Service) and tried to publish a content type everything worked fine. But doing the same thing using the newer host header resulted in the “No valid proxy can be found” message.

So if you get the”No valid proxy can be found” message and the Content Type Hub url in the Managed Metadata Service looks OK, take a look at your host headers in IIS and alternate access mappings in SharePoint.

Ian Docking – Senior Technical Consultant