sources.list is not updated properly
Users who installed 0810 beta or earlier and possibly later may have outdated /etc/apt/sources.list files. Users may have entries like this:
deb http://deb.linuxmce.org/ubuntu/ 20dev_ubuntu main
deb http://deb.linuxmce.org/ubuntu/ replacements_debian main
When we would expect lines like this:
deb http://deb.linuxmce.org/ubuntu/ intrepid beta2
deb http://deb.linuxmce.org/ubuntu/ 20dev_ubuntu main
deb http://deb.linuxmce.org/ubuntu/ replacements_debian main
The beta 2 repository is sometimes missing, or other older (alpha) repositories are improperly included.