Rated 4 out of 5 stars

deur RainerP op Nov. 29, 2016 ·

Since the Last two updates from Thunderbird the Add-On did not sync any more.
It would be great when the developer can fix that bug!
Thanks Rainer

deur Tomasz Lewoc (ontwikkelaar) op Des. 17, 2016 ·

I just tried on 45.5 on Windows and Linux and it worked in both cases. Try creating a new Thunderbird profile and installing the add-on there.