Oh no! Remote editor used proxy files as original files!

So a remote editor didn't follow instructions to use a library that I created with proxy files already made.
Instead he just started a new library and imported the .mov proxy files. This treats the imported .mov proxy files as "original media".
So when I get back the library and relink to the original media (which are .mp4 format), it doesn't allow me to batch relink and I need to individually relink each file one at a time which would take forever! Does anyone know of a workaround? It's kind of hard to explain so I made a video that hopefully makes it a little clearer:  www.loom.com/share/6ca96bac8f324c07acab0979a68c1b69

I might be inclined to re-wrap the originals in .mov containers, assuming those files aren't already linked to other projects. I'd use EditReady for this, but you could use Compressor. Just set 'pass-through' for audio and video streams.

Once the re-wrap is done, ditch the .mp4 versions (or save 'em as backup/source/whatever).

I haven't tried this but I wonder if exporting the project as an XML and doing a find and replace of mp4 to mov might work?

I usually prefer "File -> Relink Files -> Original Media..." by first selecting the Library or an Event in the Sidebar rather than in a Project/timeline, or selecting files manually in the Browser list.

I regularly switch between different "original media", regardless of file type, and haven't run into a situation where files in the same folder hierarchy weren't automatically included in the relink operation.

However, I've noticed that when you choose the files to relink and the relink dialogue window opens, sometimes you need to click in the list box and select all of the listed files. Then, once you have "located" the files to relink to, all of them should relink as a batch (instead of one at a time)...

A bit of an addendum... what follows may be relevant to the OP's situation...

Some cameras don't create MP4 files with an actual timecode track. This can include cameras like the Sony a7s series. Since FCP requires valid, matching timecode for relinking, unaltered MP4 files may not relink. A way around this issue is to use something like EditReady, which can rewrap (not transcode) the original files into something with valid timecode. This is a very quick process.

Here's a fairly thorough explanation of the timecode issue:

#118901