Thanks for taking your time.At its simplest, it means that the resources available to edit the clip/timeline can't keep up. So frames drop. There can be a lot of reasons - others apps taking resources, the video format you're working with, and so on.
Can you provide a bit more on what you're doing?
If the new machine is running a more recent OS than your MacBook, some of the underlying codec/video transcode apps were dropped in newer OSs. Or perhaps you had the notifications turned off?
You can turn the warning off if you don't want to be bothered by it. It only affects playback while editing, the shared video should be fine.
Before getting my iMac Pro, I'd often convert video to ProRes before editing, as it seemed that FCPX used a lot of resources to process through any little video defect.
If you’re still interested in an answer, can you post details about the file? If it’s a screen recording, is it from your new machine? I’ve had problems with recorded chats, for example, that had wacky frame rates. FCP X was usually pretty good at handling them, but maybe yours is particularly troublesome. Converting to another format is a good idea, one that FCP can handle better.
Yeah, it’s a highly compressed mp4, no doubt with a variable frame rate. FCP is probably just getting confused because it’s looking for constant frames based on your timeline, like 24p or 60p. I wouldn’t worry about it. If you keep seeing this error with camera-originated clips, it could signal a problem, but if it’s raw from zoom, you could transcode it to a standard constant frame rate clip, it should be fine. If it’s not doing this with other clips, I don’t think there’s any problem with your computer.