XKit 7.4.4 is now available for Firefox 29 and up. It brings compatibility with Firefox 31 and above, so if you are on version 30, please upgrade before Firefox 31 is released.

If you are on Firefox 28 or below, unfortunately, this version breaks XKit on your browser. In a nutshell, Firefox 31 brings changes that used to break XKit, so I had to rewrite parts of XKit to make it compatible with it, which in turn broke it on Firefox 29 and 30, prompting me to make more changes, which in turn, due to the way they changed things, made it incompatible with version 28 and below.

If you are on Firefox 28, you can still download XKit 7.4.3 from this link.

If you are on Firefox 29 or above, just re-download XKit and it will upgrade itself, preserving your settings.