Will not pass media selection

I have just downloaded this software to my PC and first impressions aren't the best at the moment.

It asked me to select the media for my video, I highlighted all that I needed and continued. I've had the buffer bar with 0% progress for the last 5 minutes now and I decided to force close the app from Task Manager. - I reopened the app again and this time it freezes on the gray screen with four unclickable options to the left hand side and a buffer in the center.