Virus definition not updating
This will initiate a Windows Defender update which, hopefully, will be successful.
If all else fails, you can try downloading the latest update package for Windows Defender manually as a last resort. Wait for the update package to be fully downloaded.
2) Live Update Installer shipped with the release of SEP in use.
C:\Program Files\Symantec\Symantec Endpoint Protection Manager\bin Type the following commands: lucatalog -cleanup lucatalog -forcedupdate Step 5) Apply latest certified definitions.
Move the file previously downloaded into this folder (or the relevant folder for the installation) C:\Program Files\Symantec\Symantec Endpoint Protection Manager\data\inbox\content\incoming File will be processed, and within a few minutes virus definitions will be updated on the SEPM Console and to the respective clients.
Type cd /d “\Program Files\Windows Defender” into the Command Prompt and press the Enter key.
Type exe -signatureupdate into the Command Prompt and press the Enter key.