Thanks for the reply, Guilhem. After restoring my VM back to Debian 11.7, I then tried upgrading Roundcube, first:
# sed -i s/bullseye/bookworm/ /etc/apt/sources.list # apt-get install roundcube-core This worked. I then was able to do the full upgrade to bookworm. While I'm not sure why this worked, I'm happy to get the upgrade completed. Thanks, Bryan
