FCPX wont attempt sync

FCPX has all of the sudden stopped creating synced multicam clips. I've trashed prefs, uninstalled, etc. I cant figure this out and it's an essential part of my workflow. I've read on a few other forums where people have had this issue. This sint a one off thing either, every time, no matter the situation. Look at this! -

I've never seen that before. Can you hear the audio if played? What are the audio characteristics in the inspector for the problem clips?
Is it just certain clips? What if you re-import to a test library just the two clips that failed to sync -- will they sync then? Can you import two .wav audio clips and sync those, or does all audio syncing fail on all clips, both old and new ones? Do you have another Mac to test it on? This would help determine if it's the clips, the library or something on the computer such as a plugin or kernel extension.

Just noticed that I'm having the same issue. Audio and video don't sync even though the audio is clear on both and they files are the same scene.

I'm on...

HIGH SIERRA!!!

-M

I saw someone else that couldn't even sync a copy of identical files!

Are you on High Sierra?

I'm having other issues resulting from that.

-M

are you using proxy media for syncing?

the problem varies. dslr clips won't sync together. everything is 48khz wav files or dslr with good audio.
What I noticed yesterday was that 3 files that wouldn't sync on my computer would sync one someone else that I was working on remotely with. Both are on High Sierra.

No proxy. Syncing a H1 to a Sony a7s. Never had an issue with this in any configuration. Only have one machine set up now.

So far I've only checked one library/event that I imported last month. But I have a bunch of short interviews and none of them are syncing.

-M

I have the same issue as well. Some sync OK, some out sync, and some 'hung up' during sync process.

Timing-wise, seems like that happened after my upgrade to the High Sierra. And there are also other instability issues, the worst being 'crash' whenever clicking Import Media. The latter happens only in my iMac (with Fusion Drive) but not my MacBook.

10.4 fixed this for me. But it sure sucked having high-sierra throw off my workflow.