If you are like me and have trouble typing then one thing that you might have done when setting up your Content Type Hub ( like this ) is to either make a spelling mistake in the Hub Url or simply copy the URL and get the Home.aspx at the end of it, like below:
Of course this will now not work but there is no actual way to change this through the Central Administration UI, as has been mentioned in a couple of blog posts
Then when you try to publish out the Content Types you will get an error as you don’t have a valid proxy configured.
However you can actually change the Hub URL through powershell by using:
Set-SPMetadataServiceApplication -Identity "<ServiceApplication>" -HubURI "<HubURI>"
When you try to do this you get this rather scary message:
This is SharePoint telling you that this is a major thing so be careful! Essentially all your content types that you have published out will be removed if they can, and you have to replish all of your content types out again which can cause some issue.
But we can see now that the URL has changed and after everything settles down we can publish out again:
One more thing make sure that you update the Service Connection as well to consume the content types:
But it is an option, otherwise the only thing that you can do is create another Managed Metadata Service Application