Microsoft has confirmed it has blocked Windows 10 May 2019 Update (version 1903) updates for some Mac users. Specifically, the update has been paused for users running old Mac devices and newer Mac machines running outdated Apple Boot Camp versions.

If you are unfamiliar with Boot Camp, it is an Apple software that runs Mac machines into multi-boot devices. By leveraging Boot Camp, users are able to run Windows 10 on an Apple device.

However, it seems Windows 10 May 2019 Update and older Boot Camp builds are not jiving well. Microsoft says the update is causing issues with Windows 10 1093 on Mac devices from before 2012 and those running old versions of Apple Boot Camp.

“Specifically, devices with MacHALDriver.sys dated September 24, 2011 01:57:09 or older in Windows\system32\drivers are affected,” Microsoft said.

Windows Latest reports on a support page that Microsoft seems to be keeping under wraps. While it is not private, Microsoft has blocked web crawlers from indexing the support document. It is unclear why the company has decided to do this.

Workaround

Either way, the document reveals Windows 10 May 2019 may not install on affected machines due to a compatibility problem. If a machine has a problem, the user is likely to see the following message:

“Mac HAL Driver – machaldriver.sys: Your PC has a driver or service that isn’t ready for this version of Windows 10.”

Microsoft says there is a possible workaround for the problem. That said, the way Microsoft explains it suggests the workaround may not function for everybody.

“Updating your Apple Boot Camp Windows Support Software drivers may allow you to update to Windows 10, version 1903.  You may be able to check for updated Windows support software, in macOS, choose Apple menu > App Store, then install all available updates,” the company explains

While that workaround may work, Microsoft says it is developing a fix that should be issued by the end of July.