That's a strange message if you are visiting the site in Firefox!

Could you indicate the page where this problem is occuring? Is it on the Mycroft site?

http://mycroft.mozdev.org/

While the message seems very specific, it might be an indirect indication of a different problem, such as blocked cookies.

Also make sure that you do not block JavaScript.

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

See also:

• [/questions/919992]

Loaded in Safe mode without problem. Thanks

If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

• Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
• Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

I ran into this while trying to install the Dogpile search engine extension on a brand new computer. The blocking extension was DoNotTrackPlus. I disabled DNT+, installed the Dogpile extension, and re-enabled DNT+. All is well.