After Effects Key Light Issue from PC to Mac

Hello,

Recently filmed a news pundit scene against a green screen. Just today someone helped me key out the green screen in After Effects with Key Light. It seemed to work well. I imported the comp into Premiere Pro and it worked fine on my PC at work. However, when I open the same project file on my Mac, the background is now gray and the intended background isn't showing up (see attached images below). What could be causing this? I tried playing around in both programs to no success.

Thanks in advance!