Final Cut Pro non-responsive in Tahoe OS

You already did the first troubleshooting step, deleting preferences.

You can try starting while holding the Option key, and choosing to create a new library. Add a few clips, make a few edits. Does it show the same problem? If not, then maybe it is something in the library you were working on.

Also: how much free space on your system drive, and on the drive containing your library?

Please run Etrecheck and post its full report here. Use the "additional text" button and paste the report into the text box. This will provide useful information so we can look for common causes of problems.

Thank you for responding with your concerns, atarn.

First, let’s see if this issue happens in Safe Mode:

1. Shut down your Mac.
2. Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
3. Select your startup disk. It's named Macintosh HD, unless you changed its name.
4. Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
5. Log in to your Mac. You might be asked to log in again.

If the strange behaviors do not occur, then it may possibly be a software issue.

If the issue doesn't continue in safe mode:

Leave safe mode by restarting your Mac normally, then try to reproduce the issue.

If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.

If the problem persists, then let’s try this:

• Software Update.
• Use Apple Diagnostics to test your Mac.

Need more help?

• Call 1-800-APLCARE.
• Contact Support.
• Mac Support.
• Mac User Guide.

Good luck! 👋🏼😉

If you can take a spindump when FCP is totally hung, I'll analyze it and try to see the cause. Procedure:

• Get Activity Monitor ready. Run it and select FCP.
• When the FCP hang happens, with FCP selected in Activity Monitor, do View>Run Spindump and enter your system password. This will take 10 sec or so.
• For this to be meaningful FCP, must be fully hung or in a persistent "beachball" state.
• When the spindump result is on screen, in the upper-right corner, select Save and save it as a text file. Do not open it in Word or anything else.
• Send that to me here: https://we.tl/r-X3cRrZClcI

Within one day of getting that, I will post the results here.

Your internal SSD also needs to have at least 10% free space.

Also download the free version of etrecheck, run it and post the results here as per instructions.

It's perfectly safe and was developed by a respected member of this community for troubleshooting.

https://etrecheck.com/en/index.html