Typically you should post in the Financial Management Forum as you will reach the FM SME's more there than in the Planning forum.
From Oracle Support - per Support Document: ID 1062307.1
[None] member of Entity dimension has been assigned a security class to which the user has no access.
When first connecting to Financial Management application from Smartview, the Point of View defaults to top hierarchy members. Smartview users require at least Read access to each of these members, e.g. the [None] member of the Entity dimension.
Grant users at least Read access to security class associated with [None] member of Entity dimension.
The same applies to every dimension for which security classes may be assigned and where the UseSecurityFor...option is set in AppSettings.