Do I need the "Legacy System Extension" that came with my 2019 MacBook Pro? My Mac is due to update tonight. I presently have Monterey 12.2.1

Hi Npaul71,

Great question! While we'd like to help get it answered, but we'll need more details:

1. We're unsure of what you're referring to regarding 'Legacy System Extension'. We also understand that you have macOS 10.13 installed, but are considering updating to macOS 12.2.1. What exactly is it that you're asking, and what did you mean by 'Legacy System Extension'?
2. If this is a question about compatibility with apps you use on your Mac, we recommend checking with the app developers to see if those apps are compatible with macOS 12.2.1. In case it's needed, check out the steps under 'Contact the developer of a macOS app' here: How to contact an app developer

Cheers!

I have a similar issue with my Microsoft Office 2019. I got this message. I never plan on using OneDrive. Should I just drag it out of my Applications folder. (Don’t know how to properly uninstall it.) Thanks

bruno75 wrote:

We're unsure of what you're referring to regarding 'Legacy System Extension'. We also understand that you have macOS 10.13 installed, but are considering updating to macOS 12.2.1. What exactly is it that you're asking, and what did you mean by 'Legacy System Extension'?

A "legacy system extension" is a third-party kernel extension. Apple is phasing these out as of macOS Big Sur and later, in favour of system extensions.

Every operating system has a core program called the kernel. It is the most privileged and critical program, and acts as the mediator between software (macOS and apps) and hardware. It also applies several security policies to protect the system. The macOS kernel is called XNU, and it is also used in Apple's other OSes (such as iOS).

Kernel extensions are system programs that run with kernel privileges, and extend the kernel's capabilities. Apple bundles many preinstalled kernel extensions with the kernel to make it smarter and more powerful.

Some third-party apps may provide their own kernel extensions if they need deep system access. This provides low-level control, but any programming mistakes (or security issues) can have catastrophic results.

In macOS Catalina (I think) and later, Apple is encouraging developers to move from third-party kernel extensions, to system extensions. These are similar to kernel extensions, but system extensions only run with regular app permissions, not kernel permissions. If a system extension messes up, the disaster is much more limited than a kernel extension failure.

As part of the move to system extensions, Apple is calling third-party kernel extensions "legacy system extensions". The nomenclature can be confusing sometimes.

Hi Paul,

Microsoft's uninstallation instructions say to just move the OneDrive app to the Trash. That said, some hidden resources may remain on your Mac, although they won't be in use.

It's unfortunate that Microsoft doesn't provide a proper uninstaller for OneDrive.

Hi Npaul71,

Can you please post a screenshot of the message about legacy system extensions?

If you're wondering what they are, see my reply to bruno75.