I recently kept getting this problem in Firefox:

Screen capture of error message in Firefox
Are you seeing this a lot when using Firefox / Iceweasel / etc?

If you use Firefox and have recently come across this error, fear not.  This intention of this page is to resolve these errors once and for all!

There are a few key steps to resolving it:

  1. Clear Cookies & Cache
  2. Use System Proxy
  3. Disable all Add-ons
  4. Close and restart browser
  5. Try again