Hello Jim, and welcome to the community!
I am reading through 188.8.131.52 documentation, and as for Network Security Manager clients, it specifies the following recommendations:
Note: For the Manager client, in addition to Windows 7 and Windows 8, you can also use the operating
systems mentioned for the Manager server (Windows Server 2008R2 and several 2012 editions).
Unfortunately, using Linux as a client is not supported, which would explain some of the issues you are experiencing.
However, I’ve found a way to get it working with Debian:
check your current java version with:
Ensure that you're running Oracle Java 1.7 or higher for maximum compatibility.
If your version turns out to be 1.6 or lower, please install 1.7. To do this, I used the following commands (your results may vary):
echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
apt-get install oracle-java7-installer
Ensure that Java 7 is your default version:
sudo update-alternatives --config java
And there you have it! Restart IceWeasel and browse to your NSM - on my test machine everything appeared to be fully-functional.
As for the threat analyzers - they work as well as long as you start them with Oracle Java 7 Webstart - though I can't promise that they won't be buggy.
If that doesn't work for you, my recommendation is to switch to a supported operating system and browser, and give this another shot. If you cannot switch from Debian Linux, perhaps install a Windows virtual machine for the purpose of accessing the NSM?
Thanks very much,
Technical Support Engineer
McAfee. Part of Intel Security.