You imported following File-Based Protection (Virus definition) JDB file on Symantec Endpoint Protection Manager (SEPM) 14.3 RU1 / RU1 MP1 but import fails and vdXXXXXXcore15sds.jdb.err remains in <SEPM install folder>\data\inbox\content\incoming folder.
https://www.broadcom.com/support/security-center/definitions/download/detail?gid=sep14
Symantec Endpoint Protection Manager Installations on Windows Platforms (SEP 14.0 Dark-Network Client only)
vdXXXXXXcore15sds.jdb
SEPM 14.3 RU1 (14.3.3384.1000) - 14.3 RU1 MP1 (14.3.3580.1100)
This issue is fixed in Symantec Endpoint Protection 14.3.4615.2000 (14.3 RU2). For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec software.
ESCRT-6453