Gmail Doesn't Work on New Computer

I just bought a new computer and synced my Firefox up. Everything was working okay at first for my 10 gmail accounts that I have logged in. Then, one by one, over the course of about an hour or so, they individually stopped being on the list. Eventually, none of them were listed at all and when I went under my settings, only 6 were showing, but were grayed out.

Now, none of them are showing in any fashion whatsoever - not in any menu - despite being logged in on Google.

What do I need to do to get this to work?

I even tried going back to the regular x-notifier and that immediately just had my gmail accounts in red and didn't work at all, either.

Yahoo seems to work okay.

I've tried clearing my cookies and cache. That didn't work. All it did was log me out and even by signing in again, not a single gmail account is showing up on any of my container tabs as working with x-notifier.