Dear sir, I have some problem during KOHA installation, i am using Ubuntu 12.04 desktop-i386, when i am writing the terminal, sudo apt-get install koha common, its shows following error messege root@koha-H81M-WW:/home/koha# sudo apt-get install koha-common Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: koha-common : Depends: libarchive-extract-perl but it is not installable Depends: libgd-perl but it is not installable Depends: libsereal-decoder-perl but it is not installable Depends: libsereal-encoder-perl but it is not installable E: Unable to correct problems, you have held broken packages. root@koha-H81M-WW:/home/koha# sudo apt-get install -f Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded. root@koha-H81M-WW:/home/koha# sudo apt-get install koha common Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package koha E: Unable to locate package common root@koha-H81M-WW:/home/koha# please give my suggesion, what can I do