We are creating a project that has fluid boxes. We need to have MP4 video in this project also. Can you insert a MP4 into a fluid box? or do you do this a different way?
In a fluid box you can only insert event video, not slide video. Event video plays indepenndently from Captivate and has its own control panel. Slide video is synchronized with Captivate's Timeline and can be controlled by it.
However if you are on version 11.5 it is possible to have a slide without fluid boxes in a responsive project. You set up that slide using the Position Properties panel. Of course a video cannot have its width/height ratio be changed.