Legacy System Extension warning on a Mac OS sc been

[Gwaihir]

Legacy System Extension warnings

For a while now, maybe over a period of 18 months and through several Operating System version upgrades on my Apple iMac PC, I have been seeing a warning message cropping up on screen from time to time. It happens every few months or so. My iMac is currently on Mac OS Sequoia Version 15.3.2. The most recent sight of the warning was  on 27th March 2025, and it refers to a HP System Extension.

When I first got my iMac in early 2020, I connected up a HP printer, but it was always troublesome under mac OS Catalina at the time. Apple engineers connected to my iMac over the internet back then and tried to sort out the problem, but without success. In the end I thought they had totally removed all vestiges of HP Printer software from my iMac.

I bought a Canon printer instead and it has worked faultlessly since.

But it is only with recent new versions of MacOS (e.g. Ventura, Sonoma, Sequoia) that I began to see this warning appearing as a reminder every 4 months or so.

I finally opened a new call with Apple o 27/03/2025 and they connected in and had a look. They cannot identify what HP related file is being warned about, and they pointed me to this URL ( https://support.apple.com/en-gb/120363  ) and they have informed me that I must now contact HP myself in pursuance of their bullet point which states:

• The alert may ask you to contact the developer for support because the extension needs to be updated or will be incompatible with a future version of macOS.

They (Apple) have not been able to tell me (or don’t want to tell me perhaps) what file or files could be involved but today I began investigating the iMac’s system report and found 3 files which I think might be relevant.

Information was obtained by going to Apple icon (top left) on the iMac PC and then “About This Mac” followed by “More Info” and then “System Report”

Here below are 3 images that are seen in the system report under the Apple EXTENSIONS section

2 of these 3 files seem to carry dates in April / November 2020 around which time the printer might have bene originally setup, or when shortly afterwards, all vestiges of the first HP Printer should have disappeared.

They seem to refer to KEXT files in some way and I then came across another URL related to such files.

( https://support.apple.com/en-ie/guide/deployment/depa5fb8376f/web   )

In which it is stated …

Important: Kexts are no longer recommended for macOS. Kexts risk the integrity and reliability of the operating system. Users should prefer solutions that don’t require extending the kernel and use system extensions instead.

My Questions to HP Community is

1. Can these extensions be updated or do they need to be ?

1. As I am not using a HP Fax or a HP Inkjet at all on my iMac, and if these are the files being pointed to in the Legacy System Extension warnings, then can they be removed from the system and HOW?

Here are the files as they exist in the file system in Finder on MacOS

Neither Apple nor HP seems to want to know about the problem

[Garp_senchau · Accepted solution]

@Gwaihir, Welcome to HP Support Community,

Thank you for posting your query; I’m here to help by guiding you through steps to resolve this issue

Thanks for laying that out so clearly—this is a textbook case of legacy HP kernel extensions (KEXTs) hanging around long after the hardware is gone. You're absolutely right to follow this up now that macOS Sequoia is flagging them more frequently.

The popup warning is macOS detecting HP kernel extensions (KEXTs) that are no longer supported and won’t be compatible in future macOS versions. These were part of older HP printer driver installations.

Can They Be Removed?

Yes — they can removed

I hope this helps.

Please feel free to reply here if you have any questions or if you need further clarification on any of the steps. 

Take care and have a good day. 

If my response helped, please mark it as an Accepted Solution! ✅ It helps others and spreads support. 💙 Also, tapping "Yes" on "Was this reply helpful?" makes a big difference! Thanks! 😊

Regards,