Comment 3 for bug 927987

There is something incorrect in line 45 of the file /etc/apt/sources.list, this is something you will need to investigate manually and resolve. The sources.list file is a collection of locations from which to install software and if update-manager isn't able to figure out what is in there then it can not work. If you need more help resolving this issue I'd use either the ubuntu forums or askubuntu.com. Thanks!