If you get an alert about a system extension on Mac

Some system extensions aren't compatible with current versions of macOS, or they won't be compatible with a future version of macOS. Learn what to do if your Mac shows an alert about a system extension or kernel extension.

About system extensions

System extensions work in the background to extend the functionality of your Mac. Some apps install kernel extensions, or kexts — a kind of system extension that works using older methods that aren't as secure or reliable as modern alternatives. Your Mac identifies these as legacy system extensions. In 2019, Apple informed developers that macOS Catalina 10.15 will be the last macOS to fully support legacy system extensions, and we've been working with developers to transition their software.

About alerts related to system extensions

When your Mac detects a legacy system extension, it shows an alert saying that a program loaded or tried to load a system extension signed by its developer.

• The alert might 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. You might be able to continue using the extension until then.

• The alert might inform you that the extension will damage your computer and has been blocked. Because it's blocked, any features of your app that require the extension won’t work.

• The alert might ask you to open certain settings or preferences to approve, enable, or allow the extension. Until you do so, any features of your app that require the extension won’t work.

If you get an alert about a system extension

For better security and reliability, you should no longer use legacy system extensions. Instead, contact the developer to learn:

• Whether they have an updated version of their software, or an alternative to that software, that doesn't require the extension.

• Whether they have ended their support for the extension and the software that requires it.

• How to remove or disable the extension and the consequences of doing so.

If the alert refers you to settings or preferences and you want to try to continue using the extension:

• You might be able to allow the extension in Login Items & Extensions settings (macOS Sequoia 15 or later) or Privacy & Security settings (earlier versions of macOS).

• On a Mac with Apple silicon, you might first need to use Startup Security Utility to set the security policy to Reduced Security and select "Allow user management of kernel extensions from identified developers."

Learn more

• System administrators can also use Mobile Device Management (MDM) to manage legacy system extensions.

• Technical details for developers are available in Deprecated Kernel Extensions and System Extension Alternatives.