Comment 2 for bug 1594190

The error message here states you should uninstall and then reinstall the package.

`sudo apt-get purge torbrowser-launcher && sudo apt install torbrowser-launcher` should do what you need, erasing its current configuration and installing new.

Note that Ubuntu 16.04 has entered Extended Security Maintenance, and if this is in fact a bug in the package you are unlikely to see a fix for this. It's strongly recommended you upgrade to a newer release.