Product: Synergy (all versions)
Operating system: Windows
This article applies to all versions of Synergy on macOS.
From time to time, the macOS Accessibility Security & Privacy settings will break and fail silently without showing a macOS error code (this sometimes happens when Apple releases an update to macOS). For all intents and purposes, everything looks fine...

The macOS Accessibility Security & Privacy screen showing Synergy in an enabled state
When the macOS Accessibility Security & Privacy system breaks, it causes Synergy to mysteriously stop working, often with “Error code 11”. This error code typically means that the entry for Synergy under the macOS Accessibility Security & Privacy screen has become invalid.
If the Synergy entry is not enabled: Enable it (click the check box to the left) and try to restart Synergy. If that doesn't work, try the next steps.
If the entry for Synergy is enabled, but Synergy still isn't working:
- Quit the Synergy app (top right menu icon)
- Click the Apple icon (top left)
- Open System Settings
- Click Privacy & Security (left hand menu)
- Scroll down and Click Accessibility
- If the lock at the bottom left of a pane is locked, click it to unlock the preference pane
- When prompted, enter your username and password
- Find Synergy in the list, and uncheck it (if checked)
- Re-check the Synergy entry
- Close System Settings
- Open the Synergy app
- Click Start (if using Synergy 1)
For more help using the macOS Security & Accessibility settings, check out the Apple help article, Customize your Mac with System Preferences.
If the problem is still not resolved after doing this, you may need to uninstall Synergy, remove the Privacy & Security Accessibility entry for Synergy, reboot, and then reinstall Synergy.
- Quit the Synergy app.
- Delete Synergy from your Applications folder (right click, Move to Trash/Bin).
- Go to Accessibility settings (as above)
- If the lock at the bottom left of a pane is locked, click it to unlock the preference pane
- When prompted, enter your username and password
- Find Synergy in the list, and remove it; click the remove/minus ( - ) button
- Confirm that Synergy is no longer in the list
- Reboot your Mac
- Install Synergy again
- Open the Synergy app.
- Follow the instructions to re-add and re-enable Synergy in the macOS Accessibility settings
- Click Start (if using Synergy 1)
One last thing to try before getting in touch with us...
Warning: Please only attempt this last step if you are familiar with the Terminal app.
Try running the following command from the Terminal app:
sudo tccutil reset Accessibility