This is also a problem between Ubuntu LTS versions. Specifically: I get the same error message when running unison on 20.04 (Focal Fossa) and trying to unison sync with a remote computer running 18.04 (Bionic Bever).
This is also a problem between Ubuntu LTS versions.
Specifically: I get the same error message when running unison on 20.04 (Focal Fossa) and trying to unison sync with a remote computer running 18.04 (Bionic Bever).