I am using User Role Editor to modify the Classifieds user permissions. I want to be able to prevent Classified Members from being able to access and upload media to the library. Via User Role Editor, I am able to uncheck the upload files permission. This prevents a user from uploading a file on the first try by displaying the "you don't have permission" white screen. To navigate away from this screen, you have to back arrow the browser to a screen that will allow them to upload on the second try.