Likely Cause(s):

• Potential hardware issue
• Operating system or Logitech software settings
• Application-specific or Internet browser settings
• USB port issue
• Logitech Control Center was installed or updated on macOS Mojave 10.14 or later and user permissions have not been set. See Logitech Control Center permission prompts on macOS Mojave for more information.

Symptom(s):

• Single-click results in double-click 
• Button gets stuck or responds intermittently
• The assigned function does not work
• The button doesn’t respond at all
• Forward or Back function behavior is erratic or does not work

Possible solutions:

1. Clean the button(s) with compressed air.
2. Verify the product or receiver is connected directly to the computer and not to a hub, extender, switch or something similar.
3. Unpair/repair or disconnect/reconnect hardware.
4. Upgrade firmware if available.
5. In Setpoint or Logitech Control Center:
   • Assign a different function to the button. If it works, the problem is probably application-specific. If it doesn’t work, then it may be a hardware issue. You can download Setpoint or Logitech Control Center from the Download link in the left menu panel.
6. Windows only — Try a different USB port. If it makes a difference, try updating the motherboard USB chipset driver. 
7. Try on a different computer. 
   • Windows only — if it works on a different computer, then the issue might be related to a USB chipset driver. If it doesn’t work on another computer, then it may be a hardware issue.
   • Mac only — if it works on a different Mac, then try to check for Mac OS X updates. If it doesn’t work in a different Mac, then it may be a hardware issue.

NOTE: If you have macOS Mojave 10.14 or later and the scroll wheel stopped working after you installed or updated Logitech Control Center update, please set the user permissions following these steps.