I can't export in Final Cut Pro X
I have never had this issue in Final Cut Pro before yet this time it's impossible to export.
After selecting share as a Master File, the first thing I notice is that the estimated file size is of 2Gb, this seems very large to me, bearing in mind my project is 15 minutes and mainly still images (though all images and all sound elements have effects on them).
The first few times I tried to export, the transcoding of the project was stuck at 7%. I changed a few things and it was stuck on 3 and now it's stuck on 5.
I've tried making a new project and copying everything inside the new project, I've tried deleting the render files and rendering the whole thing. (When I go into Render all it doesn't work, but selecting all then doing command + R seems to work).
I've encountered this general issue. There might be a clue in the fact that it gets hung up sooner now that you've made changes.
In my case, there was a particular thing on the timeline that caused the problem (it was just some innocuous-seeming clip), and I was able to troubleshoot by disabling entire chunks of clips to narrow it down. So maybe try disabling (V) your first 5 minutes and see if it exports ok. If it does, you know the issue is in that section. Keep disabling smaller and smaller sections until you've figured out the clip or element that's causing the problem.
In my case, I just deleted the clip from the project and reinserted it without even relinking the source media. So it seemed like it was a bug.