I am working on editing a video for a friend and I am having a problem. I am trying to add a Matte Alpha transition manually that I got from footage crate (if source matters) I have QuickTime installed. I am using the .mov file, I am trying to follow the tutorial they have on their site for it because I am still fairly new to using Hitfilm (I have the pro version). The problem is... there is no alpha transparency. It's solid black. I added Set Matte to the composite shot, I made sure it was set to Alpha, I set the source to the mov transition footage, which appears above it in the comp shot. The coloured bits when they swirl in reveal the video, but the alpha bits are solid back.
I am tearing my hair out. Any ideas what I am screwing up please?