CoreSync.exe: How to Force Stop a Stuck Sync Process

CoreSync.exe (branded as the Adobe Content Synchronizer on macOS) manages local-to-cloud file tracking, font syncing, and asset hydration. When the sync pipeline hits a corrupted sync journal, a locked local file, or a network handshake timeout, CoreSync.exe can get trapped in an aggressive validation loop. In this state, it pins CPU usage, prevents files from being edited or deleted due to active operating system locks, and causes the Creative Cloud status icon to spin endlessly without completing.

Fast Fix

Open Task Manager (Ctrl + Shift + Esc) or Activity Monitor, highlight CoreSync (or Adobe Content Synchronizer), and select End Task. Open Creative Cloud Desktop, click the Cloud icon in the upper right, and click the Pause syncing button to keep the service from immediately relaunching into the same stuck loop.

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Quick Status Snapshot

• Severity: Moderate (can prevent project saving, lock open assets, and cause high battery drain).
• System Scope: Storage subsystem and background synchronization engine.
• Associated Errors: File in use by another process; 100% CPU lock on single logical core.

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Why CoreSync Gets Stuck

CoreSync.exe maintains a local database file (built on SQLite) that maps local disk files to remote server objects. It operates using an OS-level file system watcher that triggers every time a file within a synced Adobe directory changes.

[Local File Saved]
        │
        ▼
[OS File System Watcher]
        │
        ▼
   [CoreSync.exe] ──(Checks Local DB)──► [sync.db3 / Journal]
        │                                      │
        │                                (DB Corrupted?)
        ▼                                      │
[Attempt Cloud Upload]                         ▼
        │                              [INFINITE SYNC LOOP]
        ▼
 (Socket Hangs / Locked File)

CoreSync typically enters an infinite loop for three reasons:

1. Database Journal Deadlock: A crash during a write operation leaves the SQLite journal locked, causing CoreSync to poll the database file endlessly.
2. Handle Locks: An external program (such as video rendering software or an antivirus scanner) has an open handle on an asset CoreSync is trying to inspect.
3. Third-Party Cloud Conflicts: If synced files are stored inside a path simultaneously indexed by OneDrive, Dropbox, or Google Drive, both sync engines will fight over file attributes.

If you are running macOS and seeing high battery drain and fan noise from this process, see Adobe Content Synchronizer High Power Consumption on macOS.

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Diagnostic Path: Break the Loop Safely

[CoreSync Spinning / CPU Pinned]
              │
              ├──> Is CPU high, but no files are actively being added?
              │      └── Cause: Database corruption in local sync cache.
              │      └── Next Step: Terminate CoreSync and reset sync database.
              │
              ├──> Windows throws "File In Use" error when moving folders?
              │      └── Cause: CoreSync is holding an active read handle open.
              │      └── Next Step: Kill CoreSync via command line and release locks.
              │
              └──> Sync stops completely after an internet drop?
                     └── Cause: Network adapter state desync.
                     └── Next Step: Review Error 201 network recovery steps.

If the loop was triggered after an unstable network connection drop, compare your symptoms with Error 201: Network Disconnection During Creative Cloud Sync.

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Step-by-Step Resolution

Step 1: Force Terminate via Command Line

If Task Manager fails to kill the process because it is waiting on kernel disk I/O, force termination through an elevated terminal.

On Windows:

1. Press Win + X and select Terminal (Admin) or Command Prompt (Admin).
2. Run the following command: taskkill /f /im CoreSync.exe
3. If CCXProcess.exe immediately restarts it, kill the supporting launcher: taskkill /f /im CCXProcess.exe

On macOS:

1. Open Terminal.
2. Run the following command to terminate the synchronizer process: killall -9 "CoreSync" "Adobe Content Synchronizer"

Step 2: Unlock the Stuck File Handle

If you cannot delete or move a file because Windows reports it is open in CoreSync.exe:

1. Press Win + R, type resmon.exe, and press Enter to open the Resource Monitor.
2. Click the CPU tab.
3. Expand the Associated Handles section.
4. In the Search Handles box, type the name of the locked file or folder.
5. Right-click the handle associated with CoreSync.exe and select Close Handle.

Step 3: Clear the Corrupted Sync Database

To permanently stop the loop, you must clear the local database cache that CoreSync is choking on.

On Windows:

1. Ensure CoreSync.exe is completely stopped.
2. Press Win + R, paste the following path, and click OK:
   %LocalAppData%\Adobe\CoreSync
3. Locate files ending in .db, .db3, or .journal (such as sync.db3).
4. Move these files to a temporary backup folder on your desktop, or delete them.
5. For a complete local database rebuild, follow the complete reset procedure outlined in How to Reset the Local Creative Cloud Files Database.

On macOS:

1. Terminate all sync processes.
2. Open Finder, hit Cmd + Shift + G, and paste:
   ~/Library/Application Support/Adobe/CoreSync
3. Delete the local database cache files (.db3, .db3-journal).
4. Reopen Creative Cloud Desktop and click Resume syncing.

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Environmental Conflict: Coexisting with Other Cloud Sync Engines

Running CoreSync.exe inside directories managed by third-party sync providers is a common cause of recurring sync loops.

[Adobe CoreSync] ──► Writes file metadata ◄── [Microsoft OneDrive / Dropbox]
       │                                                    │
       └── Locks file for upload                            └── Flags file change
                     │                                              │
                     └──────────────► CONFLICT ◄────────────────────┘

If your project assets or Creative Cloud legacy folders reside within a synchronized folder (like OneDrive or Dropbox), both services will trigger continuous re-indexing events. To prevent these process deadlocks, follow the environment configurations in Adobe Sync Process vs. OneDrive/Dropbox Conflicts.

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Hard Stops and Safety Precautions

• Never kill CoreSync while a critical, multi-gigabyte project save is actively transferring. Force-killing the process during a raw write operation can leave a zero-byte file on the remote destination. Confirm that the application saving the file (e.g., Premiere or Photoshop) has completely finished its local write before terminating CoreSync.exe.
• If a synced directory displays persistent red error indicators across reboots after completing these steps, the folder record in the master manifest may be out of date. Check Fixing ‘Creative Cloud Files’ Folder Red ‘X’ After 2025 Update to clear the invalid folder state.