macOS 27.2 – External media becomes unreadable when library is stored on NAS with Final Cut 12.4

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Level 1

4 points

macOS 27.2 – External media becomes unreadable when library is stored on NAS with Final Cut 12.4

Subject: Critical SMB issue with Final Cut Pro 12.4 on macOS 27.2 – External media becomes unreadable when library is stored on NAS

Description:

I am experiencing a serious issue with Final Cut Pro 12.4 on macOS 27.2 running on a Mac Studio M1 Ultra.

My professional workflow requires storing Final Cut Pro libraries directly on a NAS server using SMB.

Since updating from macOS 27.0.1 to macOS 27.2, external media linked to a Final Cut Pro library stored on the NAS can no longer be played reliably. Media may reconnect successfully but playback fails, and clips eventually become offline.

Test results:

Mac Studio M1 Ultra – macOS 27.2 – Final Cut Pro 12.4:

- Library stored on NAS + external media on NAS: DOES NOT WORK.
- Library stored on NAS + media copied inside the library: WORKS.
- Library stored locally on SSD + external media on NAS: WORKS and remains stable.

Mac M5 Max – macOS 27.0.1 – Final Cut Pro 12.4:

- Same NAS, same SMB shares and same external media: WORKS correctly.

Additional tests:

- QuickTime can play the original media files directly from the NAS.
- Creating and reading symbolic links on the NAS works.
- Creating a new Final Cut Pro library does not resolve the problem.

Expected result:

Final Cut Pro should reliably play external media stored on an SMB NAS when the library itself is also stored on that NAS.

Actual result:

External media becomes unreadable or offline when the library is stored on the NAS under macOS 27.2.

Impact:

This is a critical issue for my professional editing workflow. I need to share and access Final Cut Pro libraries directly from the NAS across multiple Macs.

The same workflow works correctly under macOS 27.0.1.

Please investigate a possible SMB-related regression introduced in macOS 27.2 affecting Final Cut Pro library access and external media playback.

Thank you.

Mac Studio (2023)

Posted on Oct 30, 2026 3:16 AM

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Answer 1

MaximeBichon Author

Level 1

4 points

Nov 1, 2026 11:28 PM in response to neuroanatomist

Thank you for your response, I was hoping that Apple Support saw this message :)

The FCP library on the SSD temporary workaround works perfectly....

Have a nice day !

Best.

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Answer 2

Top-ranking reply

neuroanatomist

Level 9

72,043 points

Oct 30, 2026 8:51 AM in response to MaximeBichon

MaximeBichon wrote:

Please investigate a possible SMB-related regression introduced in macOS 27.2 affecting Final Cut Pro library access and external media playback.

Note that this is Apple Support Communities, not Apple Support. “We” are users like you and have no power to implement any suggestions. Apple employees are generally precluded from even reading these forums, with the exception of moderators who only monitor for compliance with the T&C.

Bugs should be reported to Apple here:

Feedback - macOS - Apple

This macOS 27.2 issue affecting symbolic link behavior on SMB volumes has been reported elsewhere online. macOS 27.2 reportedly breaks the "Leave Files in Place" mechanism when the Final Cut Pro library itself resides on the NAS.

Under macOS 27.2, Final Cut Pro's internally generated symlinks—used to track external media—are interpreted as generic 1KB modified files instead of valid shortcuts, causing FCP 12.4 to lose track of the asset streams during playback.

Because your tests confirm that a local library referencing NAS media works perfectly, you can reportedly bypass this bug immediately without waiting for Apple's patch.

Immediate Actionable Workarounds

Move only your .fcpbundle library package to your Mac Studio's local SSD while leaving all source footage exactly where it is on the NAS.

Why it works: This completely sidesteps the macOS 27.2 SMB symlink bug. The local macOS file system handles the tracking links to the external NAS assets flawlessly.
Setup: In FCP, select your library, open the Library Properties inspector, click Modify Settings, and ensure the media location is explicitly pointed to your external NAS folder. You can keep your cache local to speed up timelines

Full disclosure, I am passing this along but cannot test personally. I do have an NAS accessed via SMB, and video media stored on the NAS plays fine on my Mac running 27.2, but I do not use FCP.

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