Can you share your project? It is impossible to help in these kind of cases otherwise.
When a red rectangle is shown in the layout it means that for some reason C3 is not able to create the texture it needs for display.
What is the device you are trying to run C3 on? If it is an older computer or a low end mobile device it might just not have enough memory to generate the texture. Maybe your display drivers are not up to date. It's hard to tell.
Can you see any messages when you bring up the developers console by pressing F12?
I already have shared my post, in an eariler reply
I mean, I am using a Windows 7 computer, maybe that's the problem?
I haven't tried developers console yet, but I'll go ahead and try