When you try to fill in a Managed Metadata column, the value doesn’t seem to get saved. However there’s no error in the ULS logging and Site Collection administrators are capable of seeing the value.
Consider the following scenario: I’ve created a custom list and added a Managed Metadata column to it with my Site Collection administrator. With a regular user I add an item to the list:
When I save the item everything seems fine, but when I open it up I get a blank value:
Another odd behaviour is that when you try to add a column of the type “Managed Metadata” to the list with a Full Control user, you receive an access denied page.
The cause of all this trouble is a permission issue. More precisely a permission issue on the TaxonomyHiddenList. The TaxonomyHiddenList list can be viewed by navigating to /Lists/TaxonomyHiddenList/AllItems.aspx. This list contains the details of all of the terms that are used in any managed metadata column. When you check out the permissions of the list, you’ll probably encounter only one account:
Simply grant read to the NT AUTHORITY\Authenticated Users (this is normally done by default):
And you’ll see that normal users are able to read their managed metadata values again: