Written for Synergy 3 (v3.7.2) and Synergy 1 (v1.21.4), checked 3 October 2026.
Product: Synergy 1 and Synergy 3
Operating system: macOS
On macOS 15 Sequoia and later, Synergy 1 and Synergy 3 need the macOS Local Network permission to reach your other computers. If they can't connect, check it's switched on:
- Open the Apple menu
- Select System Settings
- Go to Privacy & Security
- Find Local Network
- Locate Synergy in the list
- Toggle it to On to grant access
Also keep macOS up to date (Apple menu > System Settings > General > Software Update). The first releases of macOS 15 Sequoia had firewall and security bugs that broke network connections for many apps; Apple fixed them in later macOS 15 updates.
After updating Synergy 1 or Synergy 3, or after a restart
If it stops connecting after you update it or restart your Mac, toggle the Local Network setting off then back on again:
- Open the Apple menu
- Select System Settings
- Go to Privacy & Security
- Find Local Network
- Locate Synergy in the list
- Toggle it to Off temporarily
- Toggle it back On to fix the problem
macOS sometimes doesn't apply the permission to an updated app, or ignores it after a restart, until you do this.