Hi Tony,
Please see the official post for black screen in our Desktop application here: Black screen after initial processing, raycloud is not displayed
You will find some very good suggestions about this problem. Feel free to comment there, as we want gather all information at one place 
If your problem is related to our Cloud application (you cannot visualize your project on the Cloud ), please share the link to your project, so that we can further investigate. Also, which browser are you using?