Chrome extention stopped working

I have an extension which I use for one website which has been working correctly, then all of a sudden it has stopped working.

I believe this may be due to a chrome update. I tried the extension on one of my other computers where it also doesn't work, both running chrome version 27.0.1453.94 m. My friend is running version 26.0.1410.64 m and the extension is still working for him. This is why I believe the chrome update is the causing factor.

Can anyone help me get the extension working again?

Thanks