We currently have a user that is unable to add anything to pinned items under the file explorer pin on the task bar. The user is currently using a roaming profile and states that the issue follows him to different machines when logging in. We have tried multiple fixes in the registry along with clearing AutomaticDestination and CustomDestinations in appdata with no luck. I was able to login with my account and one other and confirm this functionality works fine on other users.
This is Windows 7 Enterprise.