Since antiX-M11 was released about 7 months ago, the first dist-upgrade/upgrade is likely to be huge. You may encounter an issue with myspell-el-gr. If you do not need Greek, before doing upgrade, remove it

apt-get purge myspell-el-gr
apt-get update
apt-get dist-upgrade

Also see bug-fixes in this announcement.

bug-fixes-for-antix-m11-t3123.html