Hi Tarq57,
This has nothing to do with settings inside your browser, this is for developers of JavaScript code to better write it for a specific javaScript machine inside a particular browser, here the JavaScript machine of Firefox. There is not much you can do, but the developer of the particular add-on has to change his code for a better one. You are not in to writing JavaScript, are you? Then above messages are just informational. But some people are interested what passes on under the hood of the browser, also security wise and want to understand why they see certain errors in the Error Console of the browser caused by third party extensions.
I for one am a tester of Minefield, the nightly new builds of Fx, and take an interest in script security, also as "luntrus" I am a regular poster in the NoScript forum thread of MozillaZine webforum. My questions to the developer of this grandiose script security extension, the unforgettable NoScript, Giorgio Maone, the builder of the only "in-browser cop" taught me a lot of things and opened my eyes up to an enormous amount of threats to the user of the browser, that most general users are unaware of or do not fully understand even, sometimes I have to further study these things because they can be rather complicated and multifaceted.
Whenever I find something that could lead to malfunctioning, new threats like using TinyURL for malicious redirects under the radar, etc. etc. I report here just for the education of those that are also interested in these subjects. So use NoScript and you are secure against existing, new and even not dreamt of threats,
polonus