Multiple videos on a single page

Hi there - I'm fairly new to Lectora, so forgive me if I am asking obvious questions!I am trying to have pages within my e-learning that contain multiple video files. For example, I may have a page that has four videos, and four buttons to launch each of these. Only one of these videos should be active at any one time, and they all should play in the same place on the screen. I have tried setting this up with multiple combinations of show/hide/play/stop/change contents actions, but when I preview this my machine reboots itself. Obviously this is making testing very frustrating for me!Is there a trick to swapping videos on a page that I am missing?If I haven't included any details that I should, please let me know.Thanks,Greg