With screen 4.4 any session that was created with <4.4 can't be reattached with 4.4. https://lists.gnu.org/archive/html/screen-users/2016-06/msg00014.html Should a warning be printed via pkg-message or during pre-install with and option to cnt-c after X seconds to allow the user to stop the install to handle any 4.3 session cleanup before installing 4.4?
A commit references this bug: Author: cy Date: Sun Jun 26 06:00:42 UTC 2016 New revision: 417511 URL: https://svnweb.freebsd.org/changeset/ports/417511 Log: Add a pkg-message note about a fix to the screen message structure field responsible for $TERM handling. It is impossible to reattach to older versions. See https://lists.gnu.org/archive/html/screen-users/2016-06/msg00014.html. PR: 210551 Changes: head/sysutils/screen/Makefile head/sysutils/screen/pkg-message