With the release of macOS 10.14.5, Apple introduces a new security feature called kext notarization. You can find information about kext notarization on the following page:
The macOS 10.14.5 update is now available. You can also get the compatible refresh build for the Mac client for version 14.2 RU1, 14.2.3335.1000 in the following ways, from MySymantec, under My Products > Endpoint Protection:
SEP_Mac.*files into your current installation of Symantec Endpoint Protection Manager.
For more information about using MySymantec, see:
The refresh build applies to on-premises clients managed through Symantec Endpoint Protection Manager and to cloud clients managed by Symantec Endpoint Protection 15.
If you upgrade to macOS 10.14.5 before you install the refresh build, the functionality of antivirus, firewall, and intrusion prevention technologies may be affected. You may experience one or more of the following issues:
You should therefore delay the operating system upgrade to macOS 10.14.5 until you can update Symantec Endpoint Protection to the 14.2 RU1 refresh build.
Note: While macOS 10.14.5 requires the 14.2 RU1 refresh build, the 14.2 RU1 refresh build also supports the same macOS versions that 14.2 RU1 (14.2.3332.1000) supports. See System requirements for Endpoint Protection 14.2 RU1 (INFO5378) for more information.