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If you use an external monitor for your Mac of any shape or size and recently updated to macOS Sierra 10.12.4, chances are you've had some trouble with Night Shift.

Common issues include:

  • the inability to configure Night Shift from your external monitor
  • Night Shift being impossible to disable (as a result of the former)
  • a substantial loss of colour quality (as a result of both of the former happening at once on some connection or screen types, most commonly DVI-D to VGA, DisplayPort, and LCD screens of all kinds.)

How do you get past these issues? Is there a way to enable access to the Night Shift pane on any display?

36

Unplug the cable and insert it again.

It works for me.

Update for Catalina (macOS 10.15): For secondary monitors, you may have to unplug primary monitor, so that the secondary monitor is the primary monitor. (Doing this once should be enough)

by @Michael_Scharf

  • This totally works! – AlexBG Jul 30 '18 at 20:40
  • 2
    Glad I tried this before the accepted answer. It worked for me. – Tom Kay Aug 14 '18 at 13:32
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    Hilariously, this works for me as well... I have 2 monitors and 1 was Night Shifting while the other was not. Only unplugging then plugging back in the buggy one didn't fix it, but unplugging then plugging back in both did. – Taylor Edmiston Oct 25 '18 at 1:27
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    Power cable, video cable or both? And from which end did you unplug it, the monitor or the Mac? Doesn't seem to be working with my Mac Mini and Acer monitors. – SamAndrew81 Jan 16 at 14:14
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    This worked for me, too. One of my 2 external LG UltraFine 5K monitors didn't make the tone warmer the first evening after installing the macOS 10.14.5 update. This had happened before, and rebooting fixed it, but this time I rebooted and that did not fix it, but googling led me here and it worked. (iMac Pro with 2 external LG 5K monitors; I unplugged the Thunderbolt 3 cable from the monitor, cursed Apple in my mind for ~10 seconds, plugged it in again and my eyes stopped bleeding.) – Mason May 25 at 10:35
7

After two days of searching, I've found a solution that allows users to get past the Night Shift incompatibility issues with external monitors. This solution helps to enable access to Night Shift on any display.

  1. Connect your external monitor, disable your internal monitor, and make sure your external monitor is set as the default.
  2. Download required files. You will need two programs (and a third optional) to proceed. The first is FixEDID, which can be found here: FixEDID, the second is DarwinDumper and can be found here: DarwinDumper, and the final (optional) one is KextWizard, found here: KextWizard
  3. Open FixEDID, wait for the fields to auto-load, and minimize FixEDID, do not close it.
  4. Open DarwinDumper, click Deselect All, check the EDID box, and click Run. You will be prompted for your password, and the dump directory will auto-open when it is done. Close DarwinDumper, and copy EDID.bin to your desktop.
  5. Unminimize FixEDID, click Open EDID Binary File, select your EDID.bin. Now in the drop down menu under that button choose the internal monitor for your model of Mac (this will usually be the first option), and click the Make button. You should have a few new files now, but you can ignore all of them except DisplayMergeNub.kext, which you will need.
  6. (Kext Wizard Version) Open Kext Wizard, click the Installation tab, click Browse, choose DisplayMergeNub.kext, and click Install. You will be asked for your password. Once it has finished reboot your Mac.
  7. (Manual Installation) Open Terminal.app and run the following command sudo mv $(whoami)/Desktop/DisplayMergeNub.kext /System/Library/Extensions/ && sudo reboot. You will be asked for your password, and your Mac will automatically reboot as soon as the operation finishes.
  8. Upon rebooting you can go to Apple > About This Mac and under the Displays tab you will find your Mac now considers your external monitor to be your internal monitor, as a result Night Shift should not be auto enabled anymore, and you can now access the Night Shift preference pane from Settings.

A Quick Note

For those who want to reverse this process so that your external monitor is no longer considered a built-in display by your Mac, you can simply run the command sudo rm /System/Library/Extensions/DisplayMergeNub.kext && sudo reboot.

As with the previous command this will ask for your password, and automatically reboot your Mac after the process is finished.

UPDATE: 01/04/2019 As of later versions of macOS 10.13 and all versions of 10.14 external displays are being recognized natively when they are the only connected display. Thus this information should be considered deprecated except to those using a secondary external display, or those running macOS versions 10.12.4-10.13.4

  • Thanks for your question and answer! :) Is this a guide you've put together yourself, or have you obtained it from another source? If another source, it'd be good to cite your source (and maybe include a link). – Monomeeth Apr 6 '17 at 4:01
  • @Monomeeth, I found FixEDID mentioned on TonyMacx86, while I was looking for a solution to the issue. There were some instructions on the site it was originally posted on (insanelymac) and the mention of it in this context. However it took me a good two days to find this programme so I decided to make a formal guide with a concise title to hopefully save people all that time searching. There was also a version of DarwinDumper that didn't work on the newest version of Sierra so I decided it best to also link the version that I know does, and a programme for convenient installation. – Alison E.E. Apr 6 '17 at 4:12
  • That's great, good job! :) I've taken the liberty of editing your question and answer just so it followed the Q&A format a little better and hopefully makes it a little easier to follow. Please correct anything I may have inadvertently stuffed up in the process. Thanks again! :) – Monomeeth Apr 6 '17 at 4:34
  • This did not work for me. In clamshell mode, external display still shows 'warm' display, with no way to turn it off. Also, I would add in step 4 that one should manually set the output directory; on my machine there were permission errors as DarwinDumper attempted to write to a locked directory. – Dan May 7 '17 at 8:50
  • user3071284 Happy to help :). @Ze'ev I tested this on an iMac, so I had never taken a closed lid into account, if possible make sure that you set the Mac not to respond to the lid being close, that way it won't register the mode change and should continue to function properly when the lid is closed. As for FixEDID's output directory I had exactly the same problem as you but with a different version of the programme. I would recommend simply trying a different release of FixEDID, as far as I can tell the issue arises due to minor changes in permission handling in different versions of macOS. – Alison E.E. May 24 '17 at 22:20
3

Download Flux. It reliably works on both internal and external monitors.

  • 4
    Flux conflicts with Night Shift and causes additional issues, and installing it would in fact only make the situation worse (I tried, it did.). It should also be noted that Flux is in no way capable of fixing system level incompatibilities between Night Shift and the macOS external display handler. This is neither a solution to the main problem (inability to access or change Night Shift settings from an external monitor) nor the main symptoms (Night Shift being perpetually enabled on external monitors, or scheduling not working on internal monitors on a Mac using external display). – Alison E.E. Apr 12 '17 at 6:04
1

After trying above solutions without success, I found the "true tone" setting in "display settings" of "system preferences", unchecked it, and external monitor became normal white again. Just in case it may help someone. I have an LG 4k with a USB-C cable.

1

What worked for me was switching cables. At first I was using a USB-C to HDMI adapter. When I changed the plug to connect the monitor with my MacBook without the adapter it started to work without any issues.

0

I have 2 UHD 4K 27" LG 27UD88-W USB-C monitors hooked up to my 2017 MacBook Pro w/ Touch Bar via a single Thunderbolt 3 cable. This is achieved by way of an Elgato Thunderbolt 3 dock. (The monitors did not have enough power for the laptop alone and wouldn't offer a reliable single-cable solution.)

I initially had issues with one of the two monitors being recognized reliably. It was always the one connected to the dock via USB-C. (The other connected via DisplayPort.) I figured this was probably some driver issue.

I installed their DualController and OnScreenControl Mac OS software. Both installers required a reboot. The reboot did seem to help. However, I'm not sure if it was the software, the reboot, or both that ultimately fixed my issue with Night Shift failing on both of the monitors. I had already rebooted the system after introducing the Elgato Dock the day before.

The moral being, I'd suggest seeking out any software packages offered by the monitor manufacturer just in case they bundle drivers with them.

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