Missing Files after FCPX Import

So I am importing files from my hard drive into FCPX for a new project. They are not coming from the camera card, but from folders stored on the hard drive. After importing, it appears in the browser with the progress circle, which then completes when the file has been imported (both optimised and proxy). However, a short time later, the file in the browser comes up as File Missing, with the error image. I haven’t done anything to the files, or moved them, or renamed them. All I did, was import them (Opt and Proxy), left the files in place (on the Hard Drive), kept the hard drive plugged in, and waited for the rest of the files to import / transcode, but some (not all of them which is weird) are coming up as missing. 
When I open the project folders on my computer, and navigate to both the High Quality Media and Proxy Folders, the aforementioned missing files are showing up Missing there.
I can’t click relink yet, as FCPX is still transcoding. I’ll try that once its done, but does anyone know what might be going on? Any help would be massively appreciated.

What's the drive, and how is it connected and formatted?

You probably don't need both optimized and proxies, maybe neither depending on the drive and media.

Its a G-Drive, Thunderbolt, Mac OS Extended.
I use proxies as its faster to edit. I was reading that maybe its better to pull the actualy files out of the M4Root folders etc, and just import them. Would that be the issue?

TrisHutchinson16 wrote:

....All I did, was import them (Opt and Proxy), left the files in place (on the Hard Drive), kept the hard drive plugged in, and waited for the rest of the files to import / transcode, but some (not all of them which is weird) are coming up as missing. When I open the project folders on my computer, and navigate to both the High Quality Media and Proxy Folders, the aforementioned missing files are showing up Missing there...I can’t click relink yet, as FCPX is still transcoding..

If the files are still transcoding and if you change the viewer to proxy, they will show as red (missing). They may show as missing if you asked to see proxies and they are still being transcoded.

If you then look inside the library under High Quality Media, the optimized media files might be missing -- as you stated, they are still transcoding. However if the FCP viewer is in "original/optimized" media mode (not proxy mode), there should be no red missing clips if the import finished -- even if transcoding continues.

As Tom said you normally don't need both optimized and proxy media. There is no quality advantage to using optimized media -- that is for performance reasons. If using 4k, in most cases using 50% ProRes Proxy media is sufficient. That generates faster than optimized media, and takes much less space. 

There is currently an FCP performance bug on Apple Silicon whereby 50% H264 proxies can be very slow to generate from 4k originals. That is only Apple Silicon (not x86) and only for 50% H264, not any other size, nor 50% ProRes Proxy.

OK thats great, thanks for all that. WHat I have done is delete the project and started again, extracting the actualy movie files out of Sony's file structure, and into their own folders (so disregarding all the other Sony folders and files), and created a new project just creating Proxies. So far it looks OK, no issues with Missing Files.
Joema, to answer your point - yes the files were still going missing even in original mode. So there must've been something going on.
I'll let you know if I have any issues going forward
Thanks!

TrisHutchinson16 wrote:

Its a G-Drive, Thunderbolt, Mac OS Extended.
I use proxies as its faster to edit. I was reading that maybe its better to pull the actualy files out of the M4Root folders etc, and just import them. Would that be the issue?

FCP typically does not permit import with "leave files in place" for tree-oriented media. While you can move the "bare" media files out of a disk copy of the folder tree and import with "leave files in place", the best practice is externally rewrap them using the 3rd-party utility EditReady, then import with "leave files in place". EditReady combines all needed metadata to a single output file in Quicktime container format, which is easier for FCP to edit. The rewrap process does not transcode so it's very fast:  hedge.video/editready

Using that procedure avoids the uncertainty of leaving behind important metadata, overall it saves space since you avoid copy to library, and often improves playback performance since FCP usually handles media in Quicktime wrappers more efficiently. FCP also does not handle clip timecode correctly for certain MP4 formats (e.g. Sony XAVC), but after rewrapping to Quicktime MOV it is handled correctly.