I have generated the gerber output layers but when I open the individual layer files they appear as text only. Is this because I am using the trial version or am I missing something??
I also have tried viewing Gerber files using CS. I can't. I have used Altium and it has a wonderful Gerber viewer built-in. I think since this is the cheap version of Altium, they don't include a Gerber viewer. It wouldn't be all too difficult to put it in there. If you need to look at your Gerber files, you'll need to either download a third party Gerber viewer or upload your files to one of the many PCB manufacturing websites that show you your layers. Unless there is something that I am totally missing about CS. I would also love to view the Gerbers. It was a great check to see that all of my layers and vias lined up properly.
Try using Viewmate form Pentalogix. https://www.pentalogix.com/t/software-products/viewmate Its free and what I use to look at gerbers from an external source.
I also use the OSHPark import to verify the gerbers. You can import them without having to order.
I have used the gEDA viewer; it is easy to enable/disable the various layers with simple checkboxes and it has a measurement tool. The Altium Gerber viewer was very good and I hope they put it in CS or make it a stand-alone tool to support CS and CircuitMaker.