You tried to add a user to a project or Preference Set, possibly to fix its permissions, and you saw the following error message:
There are no additional users available to add.
The user you're trying to add is not logged in to Windows, which is preventing you from adding that user to the project or Preference Set.
1. On a computer that has CAD and Land F/X installed, log in to Windows as the user you are trying to add.
2. Open CAD.
The user will be added to the database list. You should now be able to add that user to the project or Preference Set.