Remove Player Start

Hi All

I would like to record my flythrough but every time I click on Play this ‘box animation’ appears. I think it is player start. Is there any way to remove it? I looked through the posts but I could not find an answer. I include a link to a screenshot below.

I found out that I have a lot of things showing up when I hit play. They are only visible during game mode. During game mode I click eject and delete them or click hidden in game. They disappear but only for this one game. After I click stop and play again they reappear. Do you know how to make them not visible during game mode? I spent hours trying to work it out.