Can I change the aspect ratio if I have already started the project?

Can i change the aspect ratio if I have already started the project?

Sorry, you can not change it, but you can export it as different aspect.  When you create a new project, you can set the aspect ratio to 16:9  or 4:3 or 9:16 or any other. 

Please check the online help file below.

http://www.movie-zilla.org/Support/Manual/Create-a-Project.html