Final Cut Pro v12.2 - RegisterProExtension Crashes

[latenitefilms]

Apple Feedback Assistant ID: FB22463792

DESCRIBE THE BUG:
After updating to Final Cut Pro v12.2 I'm seeing a LOT of RegisterProExtension crashes.

Weirdly, it's happening in the Final Cut Pro Creator Studio v12.2 (subscription) application bundle, even though I'm using Final Cut Pro v12.2 (lifetime/perpetual).

Maybe a bug/regression?

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Translated Report (Full Report Below)
-------------------------------------
Process:             RegisterProExtension [4945]
Path:                /Applications/Final Cut Pro Creator Studio.app/Contents/Helpers/RegisterProExtension.app/Contents/MacOS/RegisterProExtension
Identifier:          com.apple.FinalCutApp.RegisterProExtension
Version:             1.0.1 (1)
Build Info:          ProEditorSPV-44000007037000000~3
Code Type:           ARM-64 (Native)
Role:                Non UI
Parent Process:      launchd [1]
Coalition:           com.apple.FinalCutApp.RegisterProExtension [1875]
User ID:             501

Date/Time:           2026-04-10 17:07:45.9278 +1000
Launch Time:         2026-04-10 17:07:45.8022 +1000
Hardware Model:      MacBookPro18,2
OS Version:          macOS 26.4 (25E246)
Release Type:        User

Crash Reporter Key:  CF7BEE6E-B8B3-12C6-A359-37A97C616B4B
Incident Identifier: C2CCEEA6-157C-480C-BE9B-06F95A4B745B

Time Awake Since Boot: 1000 seconds

System Integrity Protection: enabled

Triggered by Thread: 0

Exception Type:    EXC_CRASH (SIGABRT)
Exception Codes:   0x0000000000000000, 0x0000000000000000

Termination Reason:  Namespace DYLD, Code 1, Library missing
Library not loaded: @rpath/ProAppSupport.framework/Versions/A/ProAppSupport
Referenced from: <B23DC4C0-E37E-3559-8ACD-0C3FB3A170F9> /Applications/Final Cut Pro Creator Studio.app/Contents/Helpers/RegisterProExtension.app/Contents/MacOS/RegisterProExtension
Reason: , (security policy does not allow @ path expansion)
(terminated at launch; ignore backtrace)

Dyld Error Message:
  1


Thread 0 Crashed:
0   dyld                          	       0x18a741b84 __abort_with_payload + 8
1   dyld                          	       0x18a7ceefc abort_with_payload_wrapper_internal + 104
2   dyld                          	       0x18a7cef30 abort_with_payload + 16
3   dyld                          	       0x18a7614a8 dyld4::halt(char const*, dyld4::StructuredError const*) + 312
4   dyld                          	       0x18a75d6bc dyld4::prepare(dyld4::APIs&, mach_o::UnsafeHeader const*) + 4784
5   dyld                          	       0x18a75c3f0 dyld4::start(dyld4::KernelArgs*, void*, void*, unsigned long long)::$_1::operator()() const + 320
6   dyld                          	       0x18a75bd4c start + 6904

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SPECS:

• 2021 16-inch MacBook Pro (M1 Max, 64GB RAM, 8TB SSD)
• macOS Tahoe 26.4
• Final Cut Pro 12.2.0

[latenitefilms]

Claude says:

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Final Cut Pro 12.2.0: RegisterProExtension helper crashes at launch due to missing hardened-runtime flags

Symptom

RegisterProExtension (the helper bundled at Final Cut Pro.app/Contents/Helpers/RegisterProExtension.app) crashes immediately at launch on macOS 26.4 with:

Exception Type:  EXC_CRASH (SIGABRT)
Termination:     DYLD, Library missing
  Library not loaded: @rpath/ProAppSupport.framework/Versions/A/ProAppSupport
  Referenced from:    …/RegisterProExtension.app/Contents/MacOS/RegisterProExtension
  Reason:             (security policy does not allow @ path expansion)

The process aborts in dyld4::prepare before main runs. It reproduces on every launch (multiple crash reports generated within minutes of each other) and affects both the regular Final Cut Pro.app and Final Cut Pro Creator Studio.app installs because they ship the same helper binary.

Root cause

The helper binary itself was not meaningfully rewritten between 12.0.0 and 12.2.0, but its code signing flags were downgraded, and that breaks dyld's ability to load its dependencies.

	12.0.0	12.2.0
Code signing flags	0x12000(library-validation,runtime)	0x0(none)
Hardened runtime	Enabled (Runtime Version 26.2.0)	Disabled
Library validation	Enabled	Disabled
CodeDirectory version	v=20500	v=20400 (downgraded)
CodeDirectory size	851 bytes	491 bytes
Binary size	161,568 bytes	161,008 bytes
Linked dylibs	Identical	Identical
LC_RPATH entries	@executable_path/../../../../Frameworks	@executable_path/../../../../Frameworks
Team Identifier	PTN9T2S29T	PTN9T2S29T

ProAppSupport.framework itself is fine — same team ID, same signing format, same bundle layout. The problem is entirely on the helper side.

Verified with:

codesign -dv "Final Cut Pro.app/Contents/Helpers/RegisterProExtension.app"
otool -L  "Final Cut Pro.app/Contents/Helpers/RegisterProExtension.app/Contents/MacOS/RegisterProExtension"
otool -l  "Final Cut Pro.app/Contents/Helpers/RegisterProExtension.app/Contents/MacOS/RegisterProExtension" | grep -A2 LC_RPATH

Why the missing flags break it

Counterintuitive, but: on macOS 26.x, dyld's @rpath expansion policy depends on the trust category derived from the binary's code-signing flags. RegisterProExtension lives in Contents/Helpers/… inside a parent .app bundle, and it reaches its dependency by traversing up and out of its own bundle via:

@executable_path/../../../../Frameworks

Four .. segments to climb from RegisterProExtension.app/Contents/MacOS/ back up to the parent Final Cut Pro bundle's Contents/Frameworks/. dyld only allows that kind of cross-bundle @rpath resolution when the binary has hardened runtime and/or library validation establishing a trust relationship with the parent bundle.

Without those flags, dyld takes the stricter path and refuses the @ expansion — which is exactly the error in the crash log:

Reason: , (security policy does not allow @ path expansion)

In 12.0.0 the helper was signed with flags=0x12000(library-validation,runtime), so dyld allowed the expansion and it loaded fine. In 12.2.0 the flags are 0x0(none) and the load is denied.

Workarounds

1. Re-sign the helper with hardened runtime to restore the missing flags:

   codesign --force --sign - --options runtime \
     "/Applications/Final Cut Pro.app/Contents/Helpers/RegisterProExtension.app"

   The outer FCP bundle seal will need to be refreshed afterward, and the ad-hoc signature may trip other checks — verify it actually launches before relying on it.

2. Copy the 12.0.0 helper over the 12.2.0 one. The binaries differ only by a Foundation/AppKit SDK version bump, not in logic. The 12.0.0 version is signed correctly and loads the 12.2.0 ProAppSupport.framework without issues since the team ID matches.

Scope

This is limited to the RegisterProExtension helper. Final Cut Pro itself is signed correctly and runs normally — RegisterProExtension is a small standalone helper launched by launchd (not by FCP) whose job is to register the Pro Extension app services. The crashes are noisy in DiagnosticReports but do not prevent FCP from running.

Versions tested

• Final Cut Pro 12.0.0 (build 445223, ProductBuildVersion 3E222) — works
• Final Cut Pro 12.2.0 (build 447037, ProductBuildVersion 3F46b) — crashes
• macOS 26.4 (25E246) on Apple Silicon (MacBookPro18,2)

[latenitefilms]

Bert Hill writes: