Aug 31, 2015 Solution: Once you double click the DMG file it will open as a read only drive and appear under devices, if you then click on the read only drive it has opened First up, I've zero experience with macs:( i have been asked to install forticleint VPN on a users new mac. So I've downloaded the software from. Www.forticlient.com i'm t.
Once you double click the DMG file it will open as a read only drive and appear under devices, if you then click on the read only drive it has opened as there will either be a .pkg file you can double click which loads an installer menu.
If however it is just a single icon or program on it's own, then you need to drag (or copy and paste) it into the applications folder on the computer.
Once it has finished copying, you can then eject the mounted read only drive image.
Additional instructions here; http://www.howtogeek.com/177619/how-to-install-applications-on-a-mac-everything-you-need-to-know/