You have received a warning that Symantec Endpoint Protection clients have missing or corrupt definitions, from one of the following sources:
These messages would appear in the form of:
Connections to the LiveUpdate Servers have been tested as per Article ID: 15126 and determined to be normal.
For Endpoint Protection Manager (SEPM) Definitions:
See article ID: 184206 for instructions on manually deleting the content.
For Endpoint Protection (SEP) Client Definitions:
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 the manual steps found in article ID: 180682 to Manually clear the definitions in your client.
If these steps fail, enable communication module logging and set to "debug" as per article ID: 171445. Once enabled, re-attempt to run LiveUpdate. Or, if managed, wait up to 2 heartbeat cycles.
Once complete collect the resulting logs, preferably by collecting a full symdiag. Then create a case with technical support with the data attached.