After upgrading the Endpoint Protection (SEP) client to one of the SEP 14.2 versions listed in the Environment section below and rebooting to complete the upgrade, a Windows client may hang on a blank screen and not complete the boot cycle.
Due to a race condition, a scenario can occur where Application Control starts without loading the Application Control content on migration or upgrade and services are timing out.
This issue is fixed in Symantec Endpoint Protection (SEP) 14.3 RU1. For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec software here.
After using workaround 2 or 3, Application and Device Control (sysplant) can be re-enabled after completing the upgrade and ensuring that LiveUpdate has been successfully run.