Content and product updates are no longer downloaded/applied after after installing Internet Explorer 9 (IE 9) beta on a Symantec Endpoint Protection (SEP) managed client.
09/30 11:19:54  Throw Internet Exception, Error Code=12152;AH failed to read internet file
09/30 11:19:54  CInternetException: <SendUrlAndReceiveResponse:>: The server returned an invalid or unrecognized response
09/30 11:22:31  <LUThreadProc>LU item not ready - skipping download.
IE 9 introduces changes to the InternetReadFileEx API call that is part of WinINet API. These changes affect the behavior of the Symantec Management Client (SMC) service, and prevent it from properly determining if new content is available.
This issue is resolved in Symantec Endpoint Protection 11 Release Update (RU) 6 Maintenance Patch (MP) 2 (11.0.6200). For information on how to obtain the latest build of Symantec Endpoint Protection, read Obtaining the latest version of Endpoint Protection or Network Access Control 11.