Hello,
Basically this happens that for some reason when the database is not upgraded during the migration from a previous version .
In that case go to -
\Program Files\Symantec\Symantec Endpoint Protection Manager\bin (substitute Program Files (x86) in this path if working on a 64 bit system ) and run upgrade.bat then repair the Symantec Endpoint Protection Manager installation through Control Panel - Add / Remove programs.
Also, check this Article:
Error: Query failed when running Comprehensive Risk Report for 24 hours
http://www.symantec.com/docs/TECH136691
Hope this works for you!!