LG UltraFine 4K Display issues macbook pro Sleep

I have the exact same model as you, I have the LG 5K as well, I did experience a lot of crashes related to sleep and wake from sleep with the MBP with Mac OS X 10.12.2 installed, since installing/updating to 10.12.3 about 3 weeks ago I have had only 1 single crash.

I have to say that I use the touch bar very lightly, most of the time the MBP is in clamshell mode with the 5K monitor connected. My current system uptime since my last reboot (not crash) is almost 9 days. I've never used the LG app, what is the benefit of using it?

I have 2 LG ultrafine 4K screens and I am facing the "one screen is black" issue when I wake up my laptop.

I have to unplug/replug this specific screen in order to get it back. If you do that AFTER waking up the laptop it's very slow (computer undetect/redetect screen so it take a few seconds...).

A workaround (until it's fixed by Apple - still having issue with macOS 10.12.4 (16E195)) is to unplug/replug BEFORE waking up the computer. With this "trick" you "don't have any slowness when waking up the laptop.

I am still having this same issue. Its very strange because it can go as long as a week without happening. I have noticed it is always the same monitor that doesn't wake, even if I switch the cables around. This really is rather enjoying and I wonder how much time I have wanted with this issue. Theater bad point is even if it is hardware related apple is telling me they will not replace the hardware but I will have to send in for prepare. I find this disgusting after spending $3500 on a MBP and close to $1000 on the 4k monitors and they have never worked correctly since I bought it in November.

The only solution I have found (someone else did the finding) is NOT to have two sources of power present when using the LG 4K monitor. If the LG's and the MGP’s power supply are both connected, the monitor will not wake from sleep. If only the LG’s power supply is connected, no problem - well there are other problems, but not this one. So, my guess is that those of us who use two LG 4K monitors simultaneously are currently out of luck, because two power supplies are connected.

I get a kernel panic on my MBP 13" Touch Bar about 10 min after I plug in the LG UltraFine 4K at work. The machine crashes and I need to boot it again. I do not use the power adapter, so it is the only USB-C device connected.

The machine never panics at home (where I never plug it into a monitor).

Very annoying.

This may sounds strange, but I was able to fix this issue by plugging in both monitors AND the power-adapter for a while. After that I could disconnect the power-adapter and both monitors wake up after sleep.

PROBLEM FIXED!!!

LG issued a firmware update yesterday that fixes the problem. However, you must have only one of your monitors plugged in at a time for the firmware update to run. If you have two monitors plugged in, only the LG Screen Manager software is updated, not the firmware. So, update the monitors one at a time, reboot, and no more having to unplug one of the monitors upon restart or after sleep ;-)

I installed the latest version of the LG Screen Manager software and it seems to have not updated the monitor firmware; just the LG Monitor software. I say this because I'm still having the issue with only one monitor coming on after waking-up the laptop. I have rebooted my system with just one monitor and it reports the monitor software version as 3.06,3.4,5226,2.14,0.28. Can anyone tell me if this matches what their monitor reports after their monitor software updated? I'm still struggling with this issue and it is quite annoying. Thanks.

No. I sent an email to LG support and got the most ridiculous respones, not of which was relevant EXCEPT for the part that told me that there is no way to get just a firmware file and attempt an update without doing a whole reinstall of the screen saver software.

I did get it worked out this weekend. Under the assumption that residual components of earlier installations of the LG Screen Manager were preventing the latest version from being installed and operating properly I decided to use a "scorched earth" approach and install a clean version of High Sierra. I first made sure I had a good Time Machine backup, disconnected one monitor, and rebooted into recovery mode. From there I used Disk Utility to erase and reformat my main partition and then reinstalled High Sierra. When High Sierra was completing its installation I did NOT do a recovery from the Time Machine backup I had previously created; rather I created a new user and used it. Once my MBP was back up and running I immediately went to the LG support site and downloaded and installed the latest version of LG Screen Manager. Once it was installed I provided it permission to control the monitor (under the Usability preference I believe) and then started it (all still with only one monitor connected to the MBP). Once LG Screen Manager was running I went to the Monitor Status page and had it check the monitor firmware for updates. It came back and said an update was available and asked if I wanted to install it. I clicked OK and about 4 or 5 minutes later it was complete (the monitor will go blank at some point during the process). Once that was done I disconnected the first monitor and reconnected the second, went back to the Monitor Status page and repeated the process. Once both monitors were updated I shutdown the computer, connected both monitors, and rebooted. Once the machine was up I logged into the new user I created to see if both monitors came up; which they did. I then waited about 30 minutes to make sure they woke up correctly; which they did again. Once I was satisfied everything was working properly I used Migration Assistant to recover my previous user, all of my computer settings, and previously installed apps. It has been a week and so far so good.

Since you just got this, I would contact Apple support, they might give you a better answer:

https://getsupport.apple.com/

I have same issue, contacted support and engineers are looking into a solution. Should hear back hopefully tomorrow. Unbelievable and very frustrating to say the least.

I have a similar problem, my MacBook Pro 15' with Touch Bar always crashes when it is in Standby with the LG 4K UltraFine attached to it. SleepWakeFailure is usually the reason. The machine always restarts! Very frustrating. I tried resetting the SMC, NVRRAM / PRAM, booting in SaveMode, nothing worked. Now I have to reinstall macOS. VERY frustrating, especially since this monitor was created in partnership with Apple and was introduced on Stage during the Keynote!