The bug:

All of a sudden, my 2013 rMBP often perceives a left-click on my Magic Mouse 2 as a right-click.


  • "Often" ≈ every 30 seconds.

  • I have 2 different mouses: an Apple Magic Mouse 1 and an Apple Magic Mouse 2. The problem persists when using either mouse. (Only one is switched on at a time.)

  • The right-click still functions properly.

  • The built-in trackpad does not have this issue. It still functions properly.

  • I've read that the problem might be somehow related to Google Chrome. But, the problem persists (e.g., in Finder) even when Google Chrome is not running.

  • I've terminated the keyboard-remapping software, "Karabiner." I do not have the purportedly-problematic apps, "BetterTouchTool" or "Magnet," installed.

  • No peripherals are plugged into the computer.

  • As soon as I notice that the left-clicks are right-clicks, I do not touch the mouse for about 5 seconds, and the mouse goes "back to normal"... until it happens again (and the process repeats).

  • I plugged in a wired USB Dell mouse (model # 0CJ339). The wired mouse does not have the issue.

What I've tried:

  • I've disconnected and deleted my wireless keyboard as a Bluetooth device (to ensure that no other Bluetooth device is connected to my rMBP other than my mouse).

  • Turning Bluetooth on and off.

  • shift + ⌥ option + left-clicking the Bluetooth menu bar icon → Debug"Reset the Bluetooth module" & "Factory reset all connected Apple devices" & "Remove all devices"

  • Switching mouse on and off. Recharging mouse.

  • System PreferencesMouse → toggling the "Secondary Click" checkbox and ensuring that "Click on right side" is selected

    • I've discovered another bug that could be related: When "Secondary click" is set to "Click on left side" in System PreferencesMouse, the computer never perceives a right-click (no matter whether the mouse is left-clicked or right-clicked). It behaves as if the "Secondary click" checkbox is not even enabled.
  • Deleting Apple Bluetooth and mouse preference files found in ~/Library/Preferences/

  • Resetting PRAM & SMC

  • Booting in Safe Mode. (The issue still manifests in Safe Mode.)

  • Logging out of the administrator account and logging into the "Guest" user account (where the issue still manifested).

  • Repeatedly pressing the ⌃ control key on the laptop keyboard to ensure that a small piece of foreign matter is not stuck underneath this key. (When I hold down the ⌃ control key and left-click, the rMBP perceives this as a right-click 100% of the time.) Also, opening "Keyboard Viewer" to ensure that my computer does not perceive any modifier keys as being pressed when the issue occurs.

  • I do not have any other lingering Bluetooth devices in the vicinity that might interfere with the mouse.

Is there anything else that I can try, besides reinstalling the OS?

OS X El Capitan, version 10.11.6.

  • This normally happens when your bluetooth mouse battery is about to die, this has happened with me and i recharged the mouse.
    – Charan
    Commented Jul 4, 2018 at 6:50
  • @Charan I already tried recharging the Magic Mouse. Also, the issue arises with two different Magic Mice. Commented Jul 4, 2018 at 19:27

4 Answers 4



I randomly noticed that a three-finger-tap on the built-in trackpad would not pull up the dictionary entry for the selected word (like it used to).

I navigated to:

  • System PreferencesTrackpadPoint & Click tab → and saw that the "Look up & data detectors" checkbox was not enabled.

This was very strange, because this feature has always been enabled, and I never disabled it. I enabled this checkbox, and the "look-up" feature now worked.

But, this immediately made my computer stop perceiving all right-clicks (i.e., right-clicks on my mouse were always perceived as left-clicks).

So, I navigated to:

  • System PreferencesMousePoint & Click tab → and toggled the "Secondary click" checkbox off and back on.

After doing this, my computer has not perceived a left-click as a right-click again.

I still have no clue what caused the issue, or why doing the above solved it, especially considering that, for good measure, I had already previously deleted the com.apple.AppleMultitouchTrackpad.plist and com.apple.driver.AppleBluetoothMultitouch.trackpad.plist preference files.


In my case, I had placed an external keyboard on the built-in trackpad. That was messing up the mouse clicks.

  • Although this is not the answer, but this was exactly what happened with me too :-D Commented Dec 25, 2020 at 7:44

Fixed!!! I discovered that my iMac showed my old Bluetooth keyboard as well as the new one that I got because I needed a number pad. I removed the batteries from the old keyboard and the mouse is back to normal!

  • Hi, as mentioned in the original post, I had already ensured that there were no lingering Bluetooth devices in the vicinity. Commented Feb 21, 2019 at 20:26

I experienced same item as described above. I tried everything as described above.

The problem occurred suddenly this week. In the morning it was ok and then as of 09:00 am it started. I looked into YouTube movies how to repair your Magic Mouse. After trying everything possible, I eventually bought a new Magic Mouse 2. The problem remained. It cost me the whole day. I restarted my modem and removed Polar Heart monitors to be far away from my MacBook Pro as any device what could be bluetooth. I shut down my printer. I removed my Bluetooth and set it up again. The problem remained.

The next morning the problem was GONE and then started as of 11:00 am again. I was puzzled as I did not do anything.

Eventually I found out that an interior painter was doing a maintenance project in the room exactly below me. When he used his tools, it interfered with my mouse....

Pfff problem is gone, but who would have thought that would be the cause.

I hope it may help someone.

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