I have problem same with this post, i click play but the prototype can’t show in my browser, only show white blank, lunacy icon logo, bullet and share button. What i try/use :
How to fix this ?
Hello!
Currently prototypes don’t work in Firefox. You can copy the link and paste it into another browser like Chrome.
Hey, I’ve had the same problem and copy and pasting the link into chrome works. But, to make this process simpler and avoid new users having to go through extra hassle is there a way you could detect chrome on the system automatically. Or, maybe have a list of browsers to select from?
Chrome auto-selection or adding an option to choose browsers in Lunacy is a really great idea! I’ll pass it on to the team, I hope that we’ll be able to figure something out in one of the upcoming versions 
I just got the word from the devs that in the nearest updates prototypes are going to be displayed within Lunacy. So no more browser issues!
I had the same issue with Firefox. But, as soon as I uploaded the project to the cloud, it seemed to resolve itself. Not sure if this is helpful.
