I recently purchased a Zoom Q8 video camera. I’ve been recording videos of my music performances. When I try to import my .mov files into Cubase 12 I get the message “Invalid or not supported file”. All the settings match (25fps) etc. I also have a separate computer with Cubase 5 installed. I can import the same video files on that with no problem whatsoever. I’m sure there’s a simple explanation that I’m overlooking. Help please! 
Relevant info:
You’ll note that Cubase video support differs between versions 5 and 12.
I have the most success with .mov or .mp4 video. If you have to convert the video format, as long as the frame rate remains the same, syncing should not be a problem. I use Handbrake (free) to convert if needed.