video can't be imported?

I'm using a Panasonic HC-X920 camcorder to shoot video. When I try to import the footage from my memory card, Final Cut X is unable to import the footage I shot, so, just out of curiosity, I tried using iMovie (same result), and then I tried Photos. When I used Photos, I can see the clips laid out on screen, but, when I tried to import them into a brand new library, I get an error. It told me that it was 'unable to import' the videos from my memory card...

Since the equipment I'm using is a loaner from my school, I asked the people who check out the equipment about the issue, and, they still have no idea how to solve this.

The files come out of the camcorder as MTS formatted files. I don't know why this issue is so complicated. What should I do in the future if none of the Apple software will work with my footage? Thanks

(P.S.) I don't have the computer anymore. I returned it on 9/11, but, it was a 2017 MacBook Pro running macOS 10.13.6 (under the apple menu, it stated that there were 7 updates in the app store, if that would have made any difference)