Hi FCP X users, I need your help!!!! I am on FCP X 10.3.4 I have several problems with some clips. They are in my event and project in FCPX. I can use these clip and put them in my timeline.
 They are physically existing on FCP X and they are linked correctly but when I want to share my project it is impossible. 
I checked one by one my clips to find the problem. One thing I saw was that the files with problems cannot be reveal in the finder by FCP X but they exist!!!! IS it a problem of source ?of proxy? I j-have been looking for long! Any leads? Thanks a lot for your input

If I understand correctly you're saying that you can see and use all the files in a FCPX project, but when you try to share the project some files go missing, and those files are the ones that FCPX can't reveal in Finder? It's hard to be definitive without poking around in your FCPX project, but it sounds like maybe the files could be scattered around in different locations, with some in the Library and others linked as external files..? I'm not primarily a FCPX guy, but if that is the case, I'd guess one thing you might want to try might be consolidating all files (File menu > Consolidate...) into a single Library for the project.. I don't know what your level of expertise is, so I've linked to a course (above) specifically on media management in FCPX—maybe something in there will turn out to be useful.

OK thanks I ll try to follow this path. and It can help me for the future... But I consolidated the project and it worked but I couldnt share it still after. My libraries are all located on my external hard drive in a big folder divided in 2 parts ( Final cut original media and the native files from my camera that I have copied there).

Hmm—if you were able to consolidate the project and are still having a problem, you may need to be a little more specific in your description of that problem.. - What specific steps are you taking to "share" the project? - What happens then? In other words, when you say "when I want to share my project it is impossible", what does that mean—exactly what happens? Do you mean share the project as in send the work-in-progress (including all the referenced files) to another editor to work on, or do you mean Share the project as in exporting/rendering a finished file? If it's the latter, here's a link to a tech note with a few troubleshooting suggestions from Apple regarding FCPX sharing problems: https://support.apple.com/en-us/HT207791 Again, it can be difficult to diagnose an issue blind—without being able to poke around on the system—and I'm not really a FCPX guy (audio is my game), but perhaps a more detailed description will point to a particular issue..

Apple have some official advice about failed exports here: https://support.apple.com/en-au/HT207791 Here’s also another page with help: https://www.fcpx.tv/tutorials/shareexport.html If the problem is with missing media, try making a new library and dragging just your final project into it. Needed media will copy across and you might be able to spot the problem. It’s also worth noting that you’re on a really old version of FCP X, and while updating in the middle of a project can be dangerous, not updating for years opens you to serious problems too.