What this post covers
Issue: License invalid after install.
Fix: Ensure your license file matches version 14.x (not 12.x or 15.x). Contact Broadcom for conversion. Symantec Endpoint Protection Manager Download 14.3
Version 14.3 introduced mandatory security enhancements for the management console. This included support for the latest Transport Layer Security (TLS) protocols, ensuring that communication between the manager and the endpoints was encrypted to modern standards. Additionally, the download included tools for "Site Server" hardening. For large deployments, SEPM 14.3 allowed for the offloading of policy processing to remote Site Servers, ensuring that the central database was not a single point of failure and could not be easily overwhelmed by a Distributed Denial of Service (DDoS) attack aimed at the management infrastructure. Symantec Endpoint Protection Manager (SEPM) 14
The 14.3 version represents a major shift toward hybrid-cloud management and modern threat defense: Version 14