You might need to enable data access permission for it to work.

Go to about:addons, select the addon and go to permission tab and enable permission for the google translate site. For me it is "Access your data *.//translate.google.com" which should be enabled.

Does not work anymore

It is a very good extension. It improve the productivity a lot!

doesnt work anymore

Thanks for this extension. It has improved my productivity a lot!

Some keyboard layouts use the AltGr key to input diacritics. This extension interferes with that - would you consider differentiating Alt and AltGr in your code?