Rated 5 out of 5 stars

The behaviour I see is quite different, the plug-in does not work but the message I get tells me I have Javascript disabled.
I have already enabled cookies from anyone, it was no good

Update: setting javascript.enabled to true - as suggested by Philipp - did work. Thank you. Could be that the last TB update reverted the boolean ? (BTW javascript.enabled is safe, it does not enable javascript in email)

This review is for a previous version of the add-on (3.1). 

Please go to the advanced config editor and check if javascript.enabled is set to true. You can find it in the Options > Advanced > General > Config Editor.