Command+C (copy) with the left command key does not work

I'm facing a strange problem. When I type ⌘+C with the left command key, it does not work anymore. The left command key is working for ⌘+V or ⌘+X or any others so it's not a hardware problem.

The C key is working too. The right command key is working for ⌘+C.

I tried changing keyboard language, adding a shortcut, reset NVRAM, activated/deactivated VoiceOver (tip found on a site) to no avail. I'm on a MacBook Pro with Mavericks.

Make sure when you press CMD+C your Edit menu in the top flashes, this indicates it works as expected.

If it doesn't, go to Keyboard settings in System Preferences and:

• Restore defaults Modifier Keys...,
• Restore defaults in Shortcuts tab,
• In App Shortcuts click the + button and test if Keyboard Shortcut input box will react on your combination.

If Edit menu flashes and it still doesn't work, then the first thing to do is to restart pasteboard service by the following commands:

launchctl stop com.apple.pboard
launchctl start com.apple.pboard

If still doesn't work, here are some other suggestions to troubleshoot the problem:

• Re-test in different applications just in case.
• Re-test if works when using contextual menu (without using the shortcut).
• Re-test alternative combination such as CMD+X for Cut instead.
• Run Console to see your System log queries if something obvious is happening.

• Test if the Clipboard works from the terminal via:

  $ echo test | pbcopy
  $ pbpaste
  

  If Paste menu item is no more greyed out, then maybe it's a problem with Paste command.

  If you're advanced user, use dtruss or fs_usage to debug it, for instance:

  $ sudo fs_usage | grep -C4 MyAppWhereCopyDoesntWork
  

  and then notice other apps which appearing exactly when you press the shortcut which potentially you could consider quitting for testing purposes.

• Disable any recent programs that you run or restart your computer.

• Disable VoiceOver as suggested here.
• Force quit the Finder (e.g.: killall -HUP Finder).
• If still doesn't work, consider rebooting the system, especially in Recovery or Safe mode to re-test.

As for a workaround, you can install Karabiner app and remap your shortcuts by configuring private.xml file (see Misc tab). For more suggestion, please check the following posts:

• Remap Ctrl+C, Ctrl+V, and Ctrl-X only
• How can I reassign the copy/paste keyboard shortcuts?

What has worked for me was force-quitting Finder (basically after trying all what you have suggested yourselves).

One of your applications may utilize the cmd+c shortcut, which is not shown in system preferences.

I have GoldenDict installed and one of its hotkeys to "Use the following hotkey to translate a word from clipboard" is "cmd+c c", which brings this problem.

Solution: use another hotkey or disable it.

It was a weird experience for me, had the same problem. After long unfruitful research through internet, I took MBP to the Genius Bar. Even they tried with networked operating systems like 10.9, 10.8 and others too. Nothing worked, later after long technical discussion they decided it may be an hardware issue (due to shorting, also option button was not working during startup OS switching). After top keyboard cover replacement it worked! Again something unexplainable, yet worked!