Okay, so this is what happened. I got Sony Vegas Pro 14.0 yesterday. I tried going on it and it worked no lag but I didn't like the video that much and I closed the software and opened it back up again. I have a video here of what keeps happpening every single time and also straight after that, it said 'Error' so I just clicked 'Okay' and it closed the software again! :c But here's the video.  As you can see aswell, there's a little bit of lag when I click on the video on that 'Open' button.  

Thanks for your help. 

-Ethan