I've had problems before when I upgraded Java on client workstation, and then trying to use SEP - for example this thread:
http://www.symantec.com/connect/forums/sep-java-console-vs-java-16019
My problems were slightly more scary though, because I found that back when I was using SEP 11 R3 or so if I upgraded my java on my client, I could no longer make packages.
The only way I could make a package was to use the console on the actual front end web server where Java was still at an older version.
Something like the workaround the article suggested also worked.
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It turns out that obviously, having an older version of Java on production machines is not best practice.
Is there anyone out there using SEP 11 RU5 or SEP 11 RU6 who can say that they're having no problems and running the last Java?
Making packages etc? I use the Network Threat Protection module but not the AV part.
(we use another vendor for the AV)