Legacy system extensions on MacBook Pro computer

The next major release of macOS will not allow third party kernel extensions. It's just warning that any third party software you're using that installs such extensions will not work in 10.16.

All vendors who now user kernel extensions will have to use a different method to load items at startup.

https://support.apple.com/en-us/HT210999

The message should have mentioned the name of the vendor the extension is from. But in short, all third party extensions are in the following location, along with a bunch of default ones installed with the OS.

/Library/Extensions

To check your system for 32-bit software, download Go64 and use it to find and remove such software. For third-party applications, I suggest you go to the developers' websites and look for 64-bit upgrades. See App Compatibility Table - RoaringApps.

You will need to restart your system and then take screenshots of the warnings when they appear. This will (hopefully) give you the name of the developer. Then you can contact the developer to see if they have an updated version of the software available (which they won't). Another alternative would be it identify exactly what you are using this software for. If you don't really need it, then uninstall it. You will mostly likely have to contact the developer do get an uninstaller tool or uninstallation instructions. In most cases, you cannot uninstall this software by dragging an app to the trash. Do NOT use an "app zapper" or "clean up" app.

This has nothing to do with 32-bit / 64-bit software. 😄

Surely there must be a better way than taking a screenshot after booting. I actually saw two alerts: one about an "unknown developer" ... and one about "Cisco". Trouble is I have 3 applications branded by Cisco.

I would expect at least some command line tool to list the exact applications concerned (not just the developers)

I understand that, but I can't even get the list of the specific kexts that are considered as "legacy". I understand this is a transition phase ... but I worry that Apple will just move ahead and force them out in the next Catalina update, then tell us: "we told you so". As it is we are in the dark ...

At the minimum, I would have liked some diagnostic tools to let me find out what kernel extensions are concerned - their name may give a clue as to who the developer is and what application uses it. Another helpful tooling would be to log every time some application uses one of the suspicious kernel extensions. Hopefully that is coming soon.

but I worry that Apple will just move ahead and force them out in the next Catalina update, then tell us: "we told you so". As it is we are in the dark ...

No we aren't. Apple is being completely up front about it. The same way they warned users through both High Sierra and Mojave that 32 bit apps were on their last legs.

uses one of the suspicious kernel extensions.

It would only be suspicious if you didn't install it. You know one was installed for a Cisco device you use (or used to), and for the other, the vendor was too lazy to put their name in the extension.

These ten are installed by the OS:

ACS6x.kext

ArcMSR.kext

ATTOCelerityFC8.kext

ATTOExpressSASHBA2.kext

ATTOExpressSASRAID2.kext

CalDigitHDProDrv.kext

HighPointIOP.kext

HighPointRR.kext

PromiseSTEX.kext

SoftRAID.kext

Any others you see in the /Library/Extensions/ folder will all be third party.

You can go to the Apple Menu > About This Mac > System Report > Software > Extensions to get a list of all of your kernel extensions. Sort the list by "Obtained from". Look for "Unknown" and "Identified developer". And maybe focus on those that say "Notarized = No".

This isn't going to explicitly show you which ones trigger those dialog messages. But 3rd party kernel extension is something that is going to give you trouble in the future, assuming it isn't already causing problems.

Apple isn't going to force them out in the next Catalina update. They still work, they are just deprecated. The notice is there to encourage you to contact the developer. Unfortunately, Apple has deprecated these kinds of things several times in the past. Usually, Apple announced the deprecation to developers only. Then, nine years later, Apple removes support for the old software. People suddenly complain because their software and hardware doesn't work anymore. So, since developers have proven that they won't listen to Apple, Apple is hoping that they will listen to their own customers. And, if nothing else, Apple is giving those customers its own warning that their software isn't going to work in the future.

Unfortunately, there is no definitive link between kernel extensions and apps. Many apps share popular open-source kernel extensions. If you post screen shots and output from System Information here in Apple Support Communities, then we will help you track down those apps. Essentially, we are that diagnostic tool.

I do not use any Cisco device. The only Cisco-branded software I have is Cisco Webex I use occasionally for web conferencing, and that uses a VOIP component (Cisco Jabber). And also a Cisco VPN for connecting to my company’s intranet. I imagine the culprit is likely the VPN (it makes sense that it would need a kernel extension). I have no idea what the other kext is used for ...

Yes, apologies. No physical device is necessary for a kernel extension to exist.

I downloaded Webex and the installer doesn't include a kernel extension, so it's likely from the VPN or VOIP software.

Can't make any type of guess on the other.

That’s the problem. They aren’t apps. Apple is specifically making this change so that system extension are explicitly part of apps. But for now, we are in the awkward transition phase.