Final Cut Pro export disappears from Finder

Well it took most of the day today and some of yesterday but I found the problem and corrected it. Thanks to Terry and Tom for your help through this. Terry your suggestion of exporting in pieces was the avenue that uncovered the issue. The first 30 minutes of the doc exported fine. The second 30 minutes did not. From there it was a matter of outputting smaller and smaller sections to find the problem. But it wasn’t exactly the issue I expected.

I narrowed it down to 3 clips side by side. Removing each clip one at a time and outputting found the middle of the 3 clips to be the problem. However, all 3 clips had been in the doc for a very long time, at least in a handful of the previous successful outputs. And in fact, all 3 clips were from my old camera, a Canon XF100 and all 3 were from the same day. How could one cause a problem and not the others?

But the footage is archival and quite grainy. I had applied the FCP noise reduction to all the 3. The difference was, I had inadvertently applied 2 instances of the noise reduction to the middle clip.

That was the issue! I removed the second instance of noise reduction and all is well.

I’m quite overjoyed at having found the issue but I have to say, a double noise reduction stuck a log jam in the whole thing? And no error messages? Wow, I’m surprised.

Thanks... that's my last fallback. Mostly because I'll be outputting this several more times with different audio files in the future so doing it that way going forward will be awkward and time consuming. If that's the only solution then so be it... thank you... but I'm hoping for other ideas too...

Thank you. I'm in the midst right now of doing what you suggest, new library, copy everything, paste into new project in new library. I'm about an hour into it so I'll report the results when I get them. I did try other codecs... I tried outputting to H.264 with the same result... file gone after output. If this current new library method fails then I will do as you suggest and export in pieces. I'll keep you posted and thank you.

No it's not the NAS. I'm only outputting there now to completely eliminate the space issue. The first 4 or 5 times I had the issue it was to a straight forward standalone drive, a WD in an enclosure, JBOD... so not a NAS. The problem happens on NAS and non NAS drives.

The WDs are formatted MAC OS Extended (journaled). The NAS is a QNAP 872XT (Thunderbolt) with 5 x 14TB drives in it, but I can't tell you the format of those drives. But honestly, if the drives or their format was an issue I should have encountered the problem previously no? I've been happily outputting this documentary all along with no issues.

Thank you... My latest experiment, new library, copy all clips into a new project in the new library, has failed. Now I'm exporting it in 30 minute chunks to see if there's a specific spot or clip that is causing the issue. I hope that's so because after that I'm out of ideas. Interestingly, the first time I tried to output where I had a problem, the file did not disappear. I was able to open the Quicktime and play it, but the picture ended around half way through and the rest was black. So I deleted it and reouput and that's when the files started disappearing. But it does seem that the output progress bar gets to around 45 or 50 percent, then shuts down like it's done. So hopefully the issue is some specific piece around the half way mark. I'm assuming your note about disk formats is not my issue because the typical output drive for me is not the NAS, it's the Mac formatted WD drives, which I've been outputting to for years.