It means that the user by which you are trying to connect doesn't have privileges to any of the database objects. Assign appropriate privilege to the required user and try Accessing.
I would like to inform that, I am using Postgresql on my Ubuntu PC. But last few days, i unable to access any User roles and showing error like "the given image ", Officially I am using Ubuntu 16.04 32bit, Please support ASAP, I had tried install Previous versions but "wget pages not found error 404" on postgresql websites.