You have received a warning that Symantec Endpoint Protection clients have missing or corrupt virus definitions, from one of the following sources:
Symantec Endpoint Protection (SEP)
Symantec Endpoint Protection Manager (SEPM)
Symantec Endpoint Protection 14.x
SymDiag shows the error "Some Symantec Endpoint Protection definition sets are corrupted"
SEP clients show the error "Your Virus and Spyware definitions are missing or corrupted. This computer will not be protected against viruses and spyware until new definitions are downloaded."
SEPM shows the error "Attention Required" which indicates that definitions are corrupted or that components are disabled.
There is no single cause for corrupted virus definitions.
Possible causes include:
Other software interfering with our download and extraction process
Caching proxies making changes to our definition update files
Power loss during the definition update process
You may also see this new message if new definitions have been downloaded but cannot be applied.
Reboot the system, then download and apply an Intelligent Updater for your version of Symantec Endpoint Protection. The Intelligent Updater is designed to remove existing definitions and install a fresh set. If the issue persists, follow these manual steps to remove the corrupted definitions and request replacement definitions from your Endpoint Protection Manager.
If you disable Tamper Protection with a policy change in the SEPM, force a policy update by right-clicking on the Symantec shield icon on the taskbar and choosing Update Policy.
Stop the Symantec Management Service. As an administrator, press Windows+R to open the Run box, or select Run from the Start Menu. Enter the command smc -stop to stop the service. You may see a message from Windows that virus protection has been disabled.
Navigate to the following folder and delete its contents Do not delete the folder itself.