After a clean installation of Symantec Encryption Desktop for Mac on computers running macOS 10.13.x or later, the System Extension Blocked dialog is displayed, prompting users to approve the third-party kernel extension (KEXT). If users do not approve kernel extension of Symantec Encryption Desktop for Mac signed by Symantec, the user enrollment never happens and Symantec Encryption Desktop does not work as expected.
System Extension Blocked
A program tried to load new system extension(s) signed by “Symantec”. If you want to enable these extensions, open Security & Privacy System Preferences.
macOS High Sierra includes the Secure Kernel Extension Loading feature. This feature requires that users approve any newly-installed KEXTs before they can load. If users do not approve a KEXT, the associated application fails to load. For more information, see the Apple Technical Note https://developer.apple.com/library/content/technotes/tn2459/_index.html.
To approve and load KEXT of Symantec Encryption Desktop for Mac, perform the following steps:
Note: On the Security & Privacy preferences pane, under the Allow apps downloaded from section, the message and the Allow button are displayed only for 30 minutes after the alert. After 30 minutes, the message and the Allow button are no longer displayed. To approve the KEXT of Symantec Encryption Desktop for Mac later, users must manually navigate to the Security & Privacy preferences pane and click the Allow button. Unless users approve, Symantec Encryption Desktop cannot be used.