Entirely broken on macOS Sierra with MBP 2016

[masc3d]

Disabled monitor will either turn on again immediately (while still showing as disabled in DisableMonitor) or the disabled monitor will show a black screen, sometimes even a frozen cursor, instead of turning off.

It will at all time remain visible in the display preferences and also continue to consume GPU processing power.

Tested with

• Macbook Pro 2016 15", OSX 10.12.3
• LG Ultrafine 5K
• Eizo EV2736W

Issue occurs with either LG or Eizo connected.

[mcsieber]

I observe the same behavior.
MacBook Pro 13" mid-2012 OSX 10.12.4
DELL U2412M (1920x1200) Thunderbolt -> DVI connection

FWIW, here are excerpts of the console messages when attempting to disable the second monitor:

error 19:00:28.509815 -0400 WindowServer [ERROR] - Driver reported mode info is out of sync with current mode info. Display 42731c0, driver's bytePerRow = 5120, driver's width = 1680, stored width = 1680. Forcing rowbytes to be 4*modeInfo->ioModeInfo.nominalwitdh.
[...]
error 19:00:28.509972 -0400 WindowServer [ERROR] - Driver reported mode info is out of sync with current mode info. Display 42731c0, driver's bytePerRow = 5120, driver's width = 2560, stored width = 2560. Forcing rowbytes to be 4*modeInfo->ioModeInfo.nominalwitdh.
[...]
error 19:00:27.450966 -0400 WindowServer [ERROR] - Driver reported mode info is out of sync with current mode info. Display 2b2855cd, driver's bytePerRow = 7680, driver's width = 2560, stored width = 2560. Forcing rowbytes to be 4*modeInfo->ioModeInfo.nominalwitdh.

[Sergiov1]

I fixed this problem with:

1. Restart & boot into the Recovery System (command+R)
2. Open Terminal from menu Utilities
3. Type csrutil disable and press return
4. Close the Terminal & restart normal