LG UltraFine 4K Display issues macbook pro Sleep

i spoke with an apple representative and the steps below seem to have fixed my issue.

Reset the System Management Controller (SMC) on your Mac - Apple Support

How to reset NVRAM on your Mac - Apple Support

I am having similar problems with crashes and panic errors due to an error in the AMD GPU (that's what the logs says), I have almost the same configuration as yours, I do not think it is a HW problem, it is a SW bug that Apple has to fix, in my case most of the GPU crashes are related to the use of the LG 5K monitor that uses the AMD GPU, mostly while the computer is in sleep mode, you can have more details in the following threads.

MacBook Pro 15" (2016) Crashing while connecting/disconnecting the LG 5K Monitor

http://forums.macrumors.com/threads/macbook-pro-15-2016-crashing-while-connectin g-disconnecting-the-lg-5k-monitor.2027944/

Same problem

http://forums.macrumors.com/threads/macbook-pro-15-2016-crashing-while-connectin g-disconnecting-the-lg-5k-monitor.2027944/

MacBook Pro 15" (2016) Crashing while connecting/disconnecting the LG 5K Monitor

I have a MBP 13" with TB and (2) LG Ultrafine 4K displays and have the exact same issue. Only (1) of the LG displays wakes from sleep. I am experiencing several sleepwakefailures per day which result in crashes and restarts. I have also experienced the loss of sound issue.

I have been in contact with Apple Support for nearly (3) weeks and still no resolution. Apple engineers conducted a capture on my MBP and sent me another MBP but the issues continue.

The fact that the monitors cannot be daisy-chained is frustrating but the fact that they do not work properly is ridiculous. Apple does not seem to have any answers so I will be returning all of the hardware.

unfortunately I'm have ing the same issues. Two LG 4G connected to my MacBook Pro (15-inch, Late 2016) and only one will wake. Even if I leave the lid open I have the same issue. My Mac is also very sluggish after waking and crashes frequently.

Same issue.

I’m running two LG 4k monitors through my 13” Pro 2016 with touchbar and they only intermittently work. I close the lid and attempt to plugin the monitors. The monitors rarely turn on when I plug them in (although when I have one running, they both appear in ‘Displays’). It’s a constant game of plug one in, if the screen doesn’t turn on, replug until it does. Then the same game with the second until I have both of my displays. As often as they work, the Macbook freezes then the SleepWakeFailure everyone is getting usually happens and a restart.

Also, every time I first plug in the monitors, their brightness always goes to 100% even though they were previously set to 75%. If I go into ‘Displays’ I see the brightest slider is still set to 75%. I then click on the slider handle in exactly the same position (so it remains 75%) and then the screens then dim from full brightness to what they should be. I have to do this every single time the monitors eventually wake.

I have a similar problem, If I leave the 5K monitor connected overnight with the MBP in sleep mode, in the morning when I take the laptop to the office and disconnect the Thunderbolt cable the MBP will crash or panic, as a workaround now before connecting or disconnecting the 5K monitor I will open the lid turn on the laptop and do the connect/disconnect with the MBP turned on, NOT in sleep mode.

I am having the exact same issue. The integration of the new MacBook Pro and the Ultrafine monitor his HORRIBLE. Throughout the day, if the computers go to sleep, the LG UltraFine will not come back on. Or, the MacBook will just restart, and the error report is SleepWakeFailure.

Not only that, but hot swap plugging (unplugging the monitor or vice versa) to pick up the laptop and take with you rarely works, causing one or the other to go blank and not come back.

Also sleep in general is very inconsistent with the new MacBook Pro 2016 with Touchbar.

All in all, the whole integration of the OS, the sleep/wake, and the new LG monitors seems like the old days when I was using a Windows laptop where none of those things were reliable.

I was always amazed at how well the Mac could hotswap on and off with Apple's Thunderbolt Display, how reliable and fast Sleep/Wake were, etc.

Now it's an utter disaster.

I am really wishing I hadn't sold top of the line MacBook Pro 2015 Retina and 27" Apple Thunderbolt Display. Those were reliable and worked perfectly all the time. The new LG and new MacBook Pro Touchbar - not so much.

So Apple, before I start wanting a refund, is this hardware or software related? Hoping software, but if not, you've got a computer and 2 LG 5K displays on their way back to you.

I’ve tried in once, and without the power-brick plugged in — only the LG 4K monitor — my 2016 15” tricked-out MacBook Pro awakened properly with the 4K monitor on. Clearly a software issue, and kudos to webdeck for discovering it.

This is actually a good solution until Apple fixes it. The only issue is that when I’m not using the LG and it has been turned off (via a power strip because there’s no power button 😠), I have to remember to plug the power-brick back in.

So it did fix my problems but I was never using the power brick.

Its just failed again after a reboot, but this time both monitors blank.

So, I went into System Preferences, Energy Saver and unchecked Automatic Graphics Switching and both monitors came to life !

I can't believe this: I called Apple Support and mentioned to them that, in addition to this LG display problem, my shiny new MBP with Touch Bar was crashing when using TimeMachine. The (very nice) person at the other end, who obviously had no clue, asked me what I was trying to do with TimeMachine. I then asked for her supervisor, who was not that much wiser and knowledgeable. I mentioned the well known (and apparently widespread) problem that shows up after the LG crash/freeze and after a TimeMachine problem, the dreaded "CATERR detected! No MCA data found."

I have a Macbook 2015 12" and purchased a LG Ultrafine K4 2 days ago. Since that time I've unplugged the power cord from the MacBook 2 times to watch TV in another room. Both times the screen was black when I opened the book and the book was unresponsive to poking. Attempts to restart with the power button failed -- the screen hung half way on the startup white horizontal line. I booted into safe mode, ran disk utility repairs (nothing showed bad), then restarted the machine. One time it restarted normally, one time with video glitches - another restart fixed that one.

All I have plugged into the Ultrafine is the power cord.

I called Apple -- they suggested SMC reboot, which I've done. I'm about 20 feet from the router and have power nap currently off.

I'll update if I figure anything out.

Same problem: Latest Macbook Pro, max configuration of memory and CPU ($4k machine) + The LG 5k display. Random crashes upon plug / unplug, loosing the sound sometimes altogether. It renders the setup completely useless! Apple, we your fix here very soon - those are your top end customers who pay extra $$ for latest and greatest only to find out it prevents them from working...

I have been having these issues consistently until I quit the LG app. I have had no issues what so ever for 3 days now. The only issue is not being able to use the split screen feature\ but I can do with out that.