Content Credentials export freezes, beachball hangs, or attachment errors on Apple Silicon M4 Macs (M4, M4 Pro, M4 Max) are caused by permission conflicts between macOS Sequoia security sandboxing, the Apple Neural Engine (ANE), and Adobe’s cryptographic manifest-signing pipeline. When Photoshop calculates perceptual hashes or contacts the local macOS Keychain to sign credentials, hardware-level memory access limits or corrupted CoreMedia caches can cause the export process to stall indefinitely at 99%.
Fast Fix
Open Photoshop, navigate to Settings > Performance, click Advanced Settings under Graphics Processor Settings, and temporarily disable GPU Compositing. Next, open System Settings > Privacy & Security > Full Disk Access on macOS, ensure Adobe Photoshop is toggled On, and re-run your export using File > Export > Export As.
Diagnostic Snapshot
| Parameter | Current System State |
|---|---|
| Hardware Affected | Apple Silicon M4 / M4 Pro / M4 Max |
| Operating System | macOS Sequoia (15.x and newer) |
| Primary Symptom | “Export As” modal freezes at “Generating Credentials…” |
| Secondary Symptom | “Content Credentials could not be attached” alert dialog |
| System Layer | Apple Neural Engine (ANE) / Unified Memory Architecture / TCC Framework |
Root Causes on M4 Apple Silicon
[Export As Triggered]
│
┌────────────────────────┴────────────────────────┐
▼ ▼
[Unified Memory / Neural Engine] [macOS Sequoia Security]
Calculates visual perceptual hashes Validates signing certificates
│ │
├─► Metal shader cache corruption ├─► TCC blocks local keychain
│ causes ANE thread timeout. │ access for background crypto.
│ │
▼ ▼
[Export Stalls at 99%] ["Attachment Failed" Alert]
1. Neural Engine & Metal Shader Collisions
Content Credentials generate a perceptual hash (a visual fingerprint) so the asset can be matched via cloud verification even if compressed later. On M4 processors, Photoshop offloads this visual hashing to the Apple Neural Engine and Metal GPU compute cores. If your local Metal shader cache becomes corrupted after a macOS or Photoshop update, the hashing thread locks up, leaving the export window unresponsive. For deeper context on Neural Engine issues, see Troubleshooting “Neural Engine” Lag in Photoshop 2026.
2. macOS Sequoia TCC (Transparency, Consent, and Control) Lockouts
macOS Sequoia introduced stricter security boundaries around inter-process communication. When Photoshop generates a C2PA manifest, it calls local background helpers to sign the digital package. If macOS flags these helper utilities or restricts access to local application support directories, Photoshop is blocked from writing the JUMBF container, triggering Fixing “Content Credentials Could Not Be Attached” Errors.
3. Rosetta 2 Translation Mismatches
If Photoshop is running natively on ARM64, but you are utilizing legacy third-party plugins or scripts running through Rosetta 2 translation, the memory addresses between the translated plugin and the native cryptographic signing engine can conflict, breaking manifest generation.
Step-by-Step Resolution Procedures
Step 1: Ensure Native ARM64 Execution
Verify Photoshop is not running under Rosetta translation:
- Quit Photoshop.
- Open Finder and navigate to
/Applications/Adobe Photoshop 2026. - Right-click the Adobe Photoshop 2026.app file and select Get Info (
Cmd+I). - Ensure the checkbox for Open using Rosetta is unchecked.
- Relaunch Photoshop.
+--------------------------------------------------------+
| Adobe Photoshop Info |
| |
| Kind: Application (Universal) |
| Size: 4.8 GB on disk |
| |
| [ ] Open using Rosetta <-- MUST BE UNCHECKED |
+--------------------------------------------------------+
Step 2: Clear Corrupted Cryptographic and Metal Caches
Stale cache files in your user library can cause the signing thread to hang:
- Quit all Adobe applications.
- Open Terminal on your Mac (found in
/Applications/Utilities/Terminal.app). - Run the following command to purge temporary Content Authenticity cache stores:
rm -rf ~/Library/Caches/Adobe/ContentAuthenticity rm -rf ~/Library/Application\ Support/Adobe/UXP/PluginsStorage/PHSP/*/PluginData/ContentCredentials - Clear the local Metal shader cache:
rm -rf ~/Library/Caches/com.adobe.Photoshop/MetalCaches - Restart your Mac.
Step 3: Grant Explicit Full Disk Access
Ensure macOS Sequoia does not block the cryptographic sub-processes:
- Open System Settings on your Mac.
- Navigate to Privacy & Security > Full Disk Access.
- Locate Adobe Photoshop 2026 and toggle it On.
- If it is already enabled, click the minus () sign to remove it, then click the plus (
+) sign to re-add it from your Applications folder. - Relaunch Photoshop and perform a test export.
Step 4: Toggle Cloud Storage vs. Local Attachment
If your local M4 secure enclave encounters write delays with very large files, switch the publishing target:
- Open Window > Content Credentials.
- Under Publishing Options, change your setting from Attach to files to Publish to Content Credentials cloud.
- Cloud publishing shifts manifest assembly and storage to Adobe’s distributed infrastructure, bypassing local JUMBF file injection on your local drive.
If working with multi-layered documents exceeding several gigabytes, also apply the performance optimizations in Fixing “Content Credentials” Lag on Large PSD Files.
Hard Stops: When to Escalate
Stop manual adjustments and contact your systems administrator or Adobe Enterprise Support if:
- Enterprise Signing Profiles are Failing: If your workstation relies on an enterprise-issued MDM profile or corporate certificate, the M4 Secure Enclave will reject manifest signatures until the administrator updates the configuration profile for macOS Sequoia.
- Kernel Panics During Export: If initiating a C2PA export triggers an Apple Silicon kernel panic (
panic(cpu 0 caller...)), the issue points to hardware-level Unified Memory faults. Run Apple Diagnostics by shutting down your Mac, holding the power button until “Loading startup options” appears, and pressingCmd+D.