Display Issue - Horizontal blue lines in application windows

Glad to hear Apple's aware of the problem. I've been having the blue screen appear once every 2-3 days while using chrome. I don't use any intensive software—only VSCode and Chrome mostly and still get the blue screen.. sometimes the issue arises while only having browser on.

I have—"Enable Power Nap", "Prevent computer from sleeping"—all turned off by default, and have always been shutting off the computer when not in use and still have the blue screen problem. But also, the computer seems to be overheating quite frequently even without using any graphics or RAM intensive programs. I can literally see the dust marks in the shape of the fan vent on the bottom bezel of the display. Hopefully this helps the Apple team work on the problem somehow..

MacBook Pro (16-inch, 2019)

Processor 2.3 GHz 8-Core Intel Core i9

Memory 16 GB 2667 MHz DDR4

Graphics AMD Radeon Pro 5500M 4GB

Intel UHD Graphics 630 1536 MB

External Display LG HDR 4K Display 27-inch

EDIT: Restarting the computer will temporarily fix the problem, but the same blue screen issue arises around—1 day to 2 days later.

Alright some update is in place. The NVRAM reset did solve the blue lines, however...

Now other problems start when an application with GPU acceleration is started and takes only 10 to 20% CPU at peaks and uses 1 or 2 % GPU. All the time my external mouse lags over the screen when it starts. Then when the fans begin to blow with a really loud sound and the MacBook gets unresponsive. Then I have to look in Activity monitor which application is using some resources and stop this application. Then the macbook is somewhat usable again.

So yes, the blue lines did not reoccur.... but it now shifted to a new problem. The 2600 Euro laptop performs like a 200 dollar Windows laptop... Please, pretty please, no really PLEASE fix this issue!

If you're getting the kernel panics (restart while asleep) you have to do this or disconnect from the external before sleep.

Personally I turned off power nap/wake from wifi and I make sure to manually put it to sleep each time, in order for me to leave it plugged in to my official Apple LG Ultrafine 4k display that also powers the machine.

I had a lot of issues with 10.15.4. The distorted screen, crashes during sleep when docked, external monitor not detected after sleep. I'm using 10.15.5 for 1 1/2 days now and all of this seems fixed (I restored energy saving settings to defaults).

So, ever since the latest update (10.15.5) I haven't had the restart problem. Also, I haven't had the blue lines ever since I did the PRAM reset a few times in a row. I'm thinking it was 2 problems (related or unrelated, who knows?).

1) Blue Lines, solved by PRAM reset

2) Sleep restarts, solved by latest updates

¯\_(ツ)_/¯

Can anyone else concur?

Also updated to v10.15.5, and have not run into the blue lines problem (but have been running into a new problem where leaving the computer on idle would cause it to “shutdown unexpectedly” instead of sleeping.. 🙃).

restarting the computer bring up the alert with a similar message-“Your Mac shutoff unexpectedly. Restore previous windows?”

but this is a whole different issue that I would have to address on a different thread 😵.

I have seen this issue with 10.15.4 the day it was released, and it is still present with 10.15.5 today.

I too am using the 16" 2019 macbook pro, and this issue does not occur with my 2018.

After a fresh reboot, it will work fine but it seems but sometimes waking from sleep causes the issue, and it can also correct it.

I do hope Apple fixes this soon. It affects Teams, Chrome, Edge, and in 10.15.4, it affected Maps as well, though that app seems to be ok in 10.15.5.

Just an update: I had the blue lines every time I connected an external monitor.

Ever since I reset the PRAM and upgraded to 10.15.5, my MacBook pro 16" runs smoothly and I no longer get the blue lines.

Reset PRAM:  pressing and holding the Command, Option, P, and R keys right as you turn the computer on.

Same here. The problem(s) seem to be fixed. I also noticed that my secondary monitor doesn't need to be unattached and reattached after it wakes from sleep anymore. I thought it was my cheap monitor cable causing that one, but seems to be fixed now too. :) Thanks Apple! Reseting PRAM was key for the "blue lines".

For me, it seems to trigger when waking from sleep, and if you have not already rebooted out of frustration, i have also found out that it can resolve itself from waking from sleep as well (though more rare).

What a frustrating problem - you invest so much in what everyone says is the latest and greatest solution and you get this kind of issue. I too am on 16 inch, 10.15.5, external monitor and am seeing this regularly on Chrome or Brave browsers.

Initially I was seeing it only once a week but it has happened several times today already. Very frustrating.

You don't know the half of it. With Chrome, Edge, and others (Teams, etc.) you can work around it by disabling Acceleration, or for the case of Chrome and Edge - set to use Metal instead. What is really annoying to me is there are some apps that just cannot be set to not be accelerated - I am a heavy user of Unity and UE4 game engines, and both exhibit this same darn problem during level development, but in a more corrupt fashion.

This only occurs on the 16" macbooks. I have now switched to my backup 2018 macbook (15" but top specs), and it does not exhibit any issues with exact same external peripherals.

I got off the phone with a customer support from Apple and he said since the issue seems to stem from Chrome, we will have to wait for Google to fix it. Glad that the next update will get this resolved though.

Same issue: Pathfinder app, YouTube, etc. all suffer from the blue lines syndrome. Worth mentioning that it's not limited to the new 16" MacBook Pro and current OS X (which I hoped would solve the problem)—this issue has persisted for the previous two OSX versions.

I also experience random overnight restarts and believe that it's related to leaving a browser window open—but I can't confirm if it's a Safari or Chrome problem. All I know is that the restarts don't happen if I close out of all browsers for the night.

The macOS 11 Big Sur Beta (1 and 2) have been a success. The issue is completely resolved, and in fact all my main issues are resolved (though one new one - no audio over my external display).

Finally.. a macOS release that works since the first developer preview, where as Catalina is still haunted with issues to this day.