You notice that Symantec Endpoint Protection (SEP) clients on Linux machines do not update their content and AutoProtect shows malfunctioning after the upgrade from version 12.x to 14.2 RU1. If you restart the machine after the uninstall of SEP 12.1 or after the upgrade to SEP 14.2 RU1 the content download as expected.
AutoProtect malfunctioning after the upgrade is due to SEP 12.x module not completely unloading from the kernel.
This issue is fixed in Symantec Endpoint Protection 14.2 RU1. The issue won't happen if you upgrade from 14.2 RU1 or newer version (e.g. 14.2 RU2). For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec Endpoint Protection.