performance problems With final cut 12.3

Question

Level 1

6 points

performance problems With final cut 12.3

Final Cut Pro 12.3 is the worst.

I updated Final Cut yesterday because I was excited about the new features

Unfortunately the update has been a huge disappointment because my projects keep bugging out

The Magnetic Mask was much better before. Now it often doesn’t understand what I’m trying to select. Every time I click the + or − brush, it selects the wrong areas.

also the Viewer suddenly goes completely black. The image only reappears while I’m adjusting the color controls, but as soon as I stop moving the sliders, it turns black again. The only temporary fix is to close the project and reopen it

On top of that, playback randomly freezes. Sometimes the Viewer gets stuck on a single frame, and even when I press the spacebar to play the timeline, nothing happens, again i have to close the project and reopen it

These are just the issues I’ve noticed so far. I’m not sure what other bugs or performance problems I’ll run into as I keep editing.

I hope they fix this as soon as possible!

MacBook Pro 13″, macOS 26.5

Posted on Jul 3, 2026 3:22 AM

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Answer 1

Jul 3, 2026 6:09 AM in response to danaj1

Delete the preferences.

Hold down the Option and Command keys as you launch FCP until a window pops up . . . then click the Delete button.

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Answer 2

Jul 3, 2026 6:35 AM in response to danaj1

As Ian said, delete your preferences and restart FCP.

I just updated to 12.3 and have had zero problems. Works just as before, and the new auto-mask tool is amazing! The new captions/subtitles feature is going to be very useful, too.

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Answer 3

BenB

Level 6

13,670 points

Jul 3, 2026 2:12 PM in response to Old_Video_Guy

I've had 12.3 do lots of bad things. Randomly seeing no image in the Viewer is one of them. Detect Edit misses cuts in my tests. And yes, the new magical AI mask is buggy for me, too. And I've not had any significant issues with FCP in a super long time, too. But, 12.3 is not stable on two MBPs here.

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Answer 4

Jul 3, 2026 6:41 AM in response to Old_Video_Guy

I have used the "Detect Edit"feature with an old sixty minute video containing hundreds of cuts.

It took less than a minute to detect them all . . . the only problem being that it is unable to detect dissolve transitions . . . otherwise it's great to re-edit old films.

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Answer 5

Jul 3, 2026 6:50 AM in response to Ian R. Brown

I am looking forward to trying the Detect Edit tool. I have a couple of old videos that were edited to tape years ago, so all I have is a single ProRes 422 file of the full video. Re-editing them will be much easier with the cuts visible in the time line.

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