Rated 5 out of 5 stars

by pippistrello on Nov. 27, 2018 ·

To make it work with Tbird 60.3.1, rename the install xpi of gContactSync to zip. Open up install.rdf and change the Thunderbird max version to 65.0. Then install extension from Thunderbird. It works again!

This review is for a previous version of the add-on (3.0.0). 

by Josh Geenen (Developer) on Dec. 4, 2018 ·

That works somewhat until TB version 63.0, then it will completely stop working. I'm tracking my progress towards supporting 63+ in https://github.com/jdgeenen/gcontactsync/issues/121. Thunderbird's rate of making breaking changes has outpaced my spare time, so your patience is appreciated.