This is always the version problem, if you upgrade to latest you wont get this message, SEP 11.x has reached EOL please upgrade to 12.1.5 ASAP
Check this document exactly the same version RU6
Symcorpui crashing on Windows 7. Error: 'Symantec AntiVirus has stopped working' while running scan.
http://www.symantec.com/business/support/index?page=content&id=TECH132902