Solved Black border around video in preview window

Hi, I'm trying to edit video taken on my Mac but the preview window is showing a large black border around the video. In the past with other video sources, I've just needed to go into pan and crop and enlarge it to fit the frame, but this isn't working this time. It enlarges the video within the little "frame" but retains the large black border. I've also tried selecting "match source ratio" and "match output ratio" and there is no change.

The video was taken with my Macbook's Photobooth app (and built in webcam) and exported from there (it's for a school project so doesn't need to be fancy video, just showing a demo I have to do). I want to edit it in Movie Studio because I need to add in some other clips from other sources to complement the main video. I'm assuming it has something to do with the file type or something, but I'm not sure how to diagnose it.

I appreciate any advice, thanks in advance.

It sounds like you have accidentally added it to the Picture in Picture video track.
This track is only meant for adding secondary videos.

Press CTRL + Shift + Q = this adds a New Video Track
You can drag new track up/down
Move video onto this new track - does it look OK now?

If you are still having problems after this, upload a copy of your .vf porject file to the forum and I will inspect your settings.
Please note that the .vf project file contains no videos and will only show me your settings!

Regards
Derek