WIN64BIT Client Install Package is missing after Symantec Endpoint Protection Manager (SEPM) upgrade to 14.3 RU3 build 5427. A client package can be added to the SEPM console manually, but it disappears after 1-3 minutes.
This error is often accompanied with a broken link in the DB with the physical file ids. See more on DB validator in
14.3 RU3 build 5427
This error was resolved in Symantec Endpoint Protection version 14.3 RU5.
This error can be resolved also by following this procedure: