It seems possible that some part of the workspace state in your user profile has been corrupted, although this is not an issue that I have seen before. Assuming that this user is not set up for any other RemoteApp and Desktop Connections feeds, we can try the following. All steps are to be done while logged in to the client machine as the user who has seen the error.After completing step 1 and 2 I could not create a new connection through control panel on a Windows 7 machine. It failed without further info (An error occurred. Contact your workplace administrator for assistance). In RemoteApp eventlog on the machine error 0x800700b7 was logged, a search pointed in the direction ERROR_ALREADY_EXISTS.1. In the registry editor, delete the contents of "HKEY_CURRENT_USER\Software\Microsoft\workspaces\Feeds\".
2. On the hard drive, delete the contents of "%USERPROFILE%\AppData\Roaming\Microsoft\Workspaces\".
3. Attempt to recreate the connection.
It turned out the startmenu RemoteApp entries were still present in the useraccount and were blocking the (re)creation of the RemoteApp connection. After deleting these folders and icons in the startmenu the new connection could be created without any further problems.
