To anyone using or who want to use @cwtch on Tails:
At some point in the Tails 6.x release cycle the "/etc/amnesia/version" file was removed - Cwtch was using this to get the OS version to properly connect to the Tor daemon.
We will get a proper fix out for this, but if you'd like to get Cwtch running on the latest Tails then you can following the guide at https://docs.cwtch.im/docs/platforms/tails - but you also need to recreate the file /etc/amnesia/version with contents "6.6 " (that last space is important)