Installing Lawson Portal for Macbook Air is done by visiting the members area of the website. Since it's not publicly available the software requires an username and password. Once you log into the members area, the client you want to download should automatically pop-up if it's not already installed onto your system. When it pop-up, click accept and let the software install using its default settings. Another way to deal with this problem is to set your browser into compatibility mode for a better support of the website.