I used Ubuntu Customization Kit to create new LiveCD for my Ubuntu 12.10 and everything is good but one. I use the command line in UCK to set some changes to the LiveCD - for example to remove software with apt-get. But when I try to use apt-get to install software (for example VLC media player) it says that it has no release candidate. What does it mean? Do I have to add manually all repositories first and install the software?