I had a problem accessing my Cisco ASDM. I would get the error, "Missing required Permissions manifest attribute in main jar". I looked around trying to find the answer, no luck, so I went onto an older machine that hadn't been updated with the latest & greatest Java.
I just tried it again, and had time to trouble shoot the error. Bill Morefield's page had the answer. I thought I would post it here to make it more easily google-able, as well as pressing this guy's site a smidgen, since it was so helpful and well written.
Basically you open the java control panel, go to security, and add the site to the exceptions. Awesome.
Bill's comment on his page... I love it...
Interestingly enough given Java’s sudden concern about
my security, it still asks to install the Ask Toolbar every update
Hilarious.