Here is the Encyclopedia Client help for user access. If this does not answer your question, please reply with more details or you can open a case with CA Support.
User Access to Specified Model
User Access allows you to grant or revoke an individual's or a group's automatic authorization to a model in the encyclopedia, as well as the model's subsets. Individuals or groups who have access to a model also have access to all subsets of the model.
It also allows the authorized user to have Read access to a model.
To grant access to some subsets but not to the entire model, use the Subset Access option instead.
If you cannot grant access to a model, verify that the user exists in the encyclopedia.
If you cannot revoke access to a model, verify that the model is checked in. The model cannot be checked out to the person whose authorization is being revoked.