Same problem here.
Release: Ubuntu 18.04.1 Package version: 1:68.2.1+build1-0ubuntu
Removing global-messages-db.sqlite is solving the problem. Before removing (when empty), the Thunderbird shows me 70.1 version number, after removing it was 68.2. Strange!
Same problem here.
Release: Ubuntu 18.04.1 1+build1- 0ubuntu
Package version: 1:68.2.
Removing global- messages- db.sqlite is solving the problem.
Before removing (when empty), the Thunderbird shows me 70.1 version number, after removing it was 68.2. Strange!