Whenever a global correlation update fails, an evError event is generated. The error message is included in sensor statistics. The following conditions result in a status message with the severity of Error:
•
The sensor is unlicensed
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No DNS or HTTP proxy server is configured
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The manifest exchange failed
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An update file download failed
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Applying or committing the update failed
For global correlation update fails, refer
http://www.cisco.com/c/en/us/support/docs/security/ips-4200-series-sensors/50360-ids-faq.html