Hi Arie,

You can contact me directly via support [at-sign] role-editor.com
Is “Activate “Create” capability for posts/pages/custom post types” checkbox turned ON at the “Settings->User Role Editor->Additional Modules”? You have to turn ON for the role the’create_NNNs’ capability, where ‘NNNs’ is the same ID, which is used by Mailster plugin for editing newsletters. So if Mailster uses ‘edit_newsletters’, then role should have ‘create_newsletters’ in order to can create new newsleters.