Final Cut Suddenly Replaced my Clips with the Wrong Files

Try relinking the clip to the correct file.

Select the clip in the browser, go to File->Relink Files->Original Media

Select "All", then select the name of the clip in the list.

Click Locate Selected... and navigate to the folder where the correct clip lives, and click Choose.

This should generally never happen. FCP has many checks to prevent this, including checking volume name, pathname, filename, inode of file, timecode of file, length of file, etc.

However if you have multiple duplicate filenames, and if that material is stored on a non-Mac format such as ExFAT, and if the file does not contain timecode, it might conceivably happen under some rare conditions. E.g, if the data is split between two disks, they have duplicate filenames, then after reboot one drive comes on line before the other normal one. Something like that might happen.

If media filenames are unique and if the volumes are either Mac OS Extended Journaled or APFS (HFS+), I've never seen this happen.

On any production (but especially large productions) it's important to have unique filenames. That can be done by Using Finder to add a 5-digit unique suffix to the files before they are imported. Finder can rename those in batches, then the next imported batch you start at +1 the last ending number.

I've worked on large documentaries with over 8,500 clips, 220 camera hours of material and 140 multi-cam interviews. If the filenames are made unique before import and all media is stored only on HFS+ or APFS volumes, FCP media management is very reliable.

I am glad that it worked, as I expected it would.

I have no idea how it got to point to the wrong file, though. Even if the file names were the same, the paths weren't... that is a mystery!

It's been reported before when original media has the same name, though I don't know why it happens. If the files are stored externally it's better to rename the files in the Finder before importing.