Random shutdown Boot Camp (Windows 10 v. 1903) when connected to LG Ultrafine 4K

There are known issues with 1903 on Macs, due to MacHALDriver.sys.

See https://support.microsoft.com/en-us/help/4510977/updating-to-windows-10-version-1903-on-apple-mac-devices-introduced-be for reference.

As a test, can you try this connection topology?

• USBc/TB3 cable that came with the monitor directly to a USBc port on the Display.
• SSDs directly connected to Mac via provided USBc cables
• Use the MBP with it's lid open
• Connect the Keyboard (or Mouse, but not both, since you have only one USBc-to-USBA adapter) via the adapter to a USBC port on the MBP (not the Display)
• This eliminates the 4-port USB-Hub (temporarily) for loss of the second HID device (Keyboard or Mouse as you choose)
• Test the system for stability

You may be 'hobbled' for a couple of days due to a lack of one of your HIDs.

tycruickshank wrote:

I actually have another USB-C to USB-A dongle so i could use the mouse, keyboard, one SSD and monitor. Is this ok for troubleshooting purposes?

Even better than what I proposed.

Let me explain the reasoning behind my topology. USB3/USBc uses 2.4gHz RF bands. If the cables are not IF-certified, they can cause interference, potentially corrupting packets. If we eliminate the third-party device, it will help us narrow down where the issue might be. The USBc-to-USBA adapter can also be potentially problematic.

The Samsung and LG cables should be IF-certified, and are not the primary suspects. I use the same cables on Samsung T3/T5s, and have not had any issues with them after 2+ years of use.

If you go back into Windows, and check the Event Viewer for date/times close to the reboot, do you see any Critical events?

tycruickshank wrote:

I do have a wired keyboard and mouse plugged into the monitor and two Samsung T5 SSDs plugged into the laptop.

Can you connect the Keyboard/Mouse to the Mac directly and test?

At one point I had the monitor plugged into a CalDigit TS3 plus thunderbolt 3 dock with the peripherals plugged into the dock. I was experiencing the same shutdown behavior.

Your BSoDs are most likely related to a timing issue.

When using the LG4K, are you connecting the Mouse Receiver dongle to the LG4K directly?

Are the USBc cables USB-IF certified?

You may just want to install 1809v2, without any other software and check if it is stable. This would eliminate any of your Application software as probable cause.

Are there any other peripherals connected to the Mac or the Monitor?

Did you upgrade from a previous W10 release to W10 1903? I am using W10 1809v2 due to issues with 1903.

tycruickshank wrote:

That's interesting. Thanks for including the reference. I wonder how much longer until Microsoft gets around to fixing it.

No worries!

Do you think that even though I was able to get 1903 installed without issue on my machine there could still be some issues present?

The primary concern is that the BC drivers which expect MacHALDriver.sys may not work as expected. This would also impact timing controls for device protocols.

On macOS I have the latest version of Mojave and presumably the latest version of Boot Camp as well.

Yes, you should get the latest BC drivers when you try to install Windows. You can check the Product version of BC drivers if you check Bootcamp.xml which is available using BC Assistant -> Action -> Download.

I will try and dig up Windows resources, but SysInternals is a good starting point.

Post back, when you can.