The only technical support articles I can find on Symantec’s website relate to making a previously unmanaged client into a managed client, which while useful, does not address the specific issue of a managed client that “breaks” and becomes unmanaged.

If you’ve had Symantec Endpoint Protection 12.1 for Mac deployed for any length of time, you’ve probably come across this message in the SEPM console “Client Version Unavailable” under the Client Version heading. After the reboot, Symantec Endpoint Protection will no longer be on the computer.Repairing symantec endpoint protection 12.1 “Client version unavailable” broken client message on Mac OS X.When it is finished, click on the Restart Now button.Enter your local mac username and password when prompted and click OK.The 'Symantec Endpoint Protection Uninstall' window will appear.With the Symantec Endpoint Protection window in view and selected, go to the top right of the menu bar and click Symantec Endpoint Protection, then click Uninstall Symantec Endpoint Protection.Click the Symantec shield in the top right corner of the menu bar, go to Symantec Endpoint Protection and then click Open Symantec Endpoint Protection.Note: We recommend that you install Avast Free Antivirus to replace Symantec Endpoint Protection

Please remove Symantec from any personally owned devices. Note: Susquehanna University has discontinued the use of Symantec Endpoint Protection, starting in Fall 2020. This document explains how to uninstall Symantec Endpoint Protection in Mac OS Symantec Endpoint Protection (Mac OS) - Uninstallation Instructions

Symantec endpoint protection mac os