Delete old kernel extensions?

TidBITS Talk
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With a MacBook Pro 2019 16-inch running Sequoia 15.1.1, after installing a SoundSource 5.75 update I received this popup alert:

“Legacy System Extension
Existing software on your system loaded a system extension signed by “HP Inc.” which will be incompatible with a future version of macOS. Contact the developer for support.”

An EasyFind search for “hp” shows two kernel extensions named <hp_io_enabler_compound.kext>, one in /Library/Extensions and the other in /Library/StagedExtensions/Library/Extensions.

I once had some HP printers but haven’t for many years now.

OK just to delete these kext files?

Thank you,

David

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Probably, but you may want to clean up the entirety of those HP drivers if you no longer have the printers.

See this HP support discussion from 2020. It describes a different problem, but includes automated (via an HP uninstaller app) and manual steps for uninstalling/reinstalling the drivers that include the HP IO-enabler kext.

The description for the manual procedure is this reply. A quick summary is:

  • Remove the printer from macOS using System Preferences (which you may already have done if you no longer use those printers)
  • Using the Finder, delete the /Library/Printers/hp folder
  • in /Library/Extensions, delete any of these kexts, if you have them:
    • hp_fax_io.kext
    • hp_inkjet1_io_enabler.kext
    • hp_io_enabler_compound.kext

(The steps after this are for reinstalling the drivers, which you don’t need to do if you have no HP printer-like devices.)

Since you also found the kexts under /Library/StagedExtensions/Library/Extensions, you may want to delete them from there as well.

If you can’t delete the kext files, consider booting into Recovery mode and deleting them from there.

Or just ignore the warning. If you’re not using it you don’t need an update. And when it actually becomes incompatible, it will simply stop working.

And I would love to know why HP thinks they need(ed?) a kext for a printer driver? Anything they need to do should be doable using the existing USB or TCP/IP system APIs.

I know HP’s drivers (at least on Windows) have a pretty robust system for detecting compatible printers installed all over a multi-site corporate network and auto-configuring those at your location, but that still shouldn’t require a kext - it’s all straightforward TCP/IP networking.

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Howard Oakley has excellent instructions for how to get rid of (or deal with) kexts on modern macOS.

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Thanks for your very helpful information, @Shamino, and also thanks to @Simon for mentioning the timely Howard Oakley article.

I downloaded and ran the HP uninstaller linked at the HP support discussion, but it didn’t remove the kexts, which are the only HP files I have except for two logs (HP Easy Start and HP Product Research).

I then manually deleted the kext in /Library/Extensions, but since the one in /Library/StagedExtensions/Library/Extensions can’t be easily deleted, as you (and Howard Oakley) suggest, I will just ignore it.

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