Software index is brokensudo apt-get update at terminal. When it tries to read package lists an error occurred. Look at the last lines at the image above. Several error message showing there.
This is a major failure of your software management system. Please check for broken packages with synaptic, check the file permissions and correctness of the file '/etc/apt/sources.list' and reload the software information with: 'sudo apt-get update' and 'sudo apt-get install -f'.
W: Envountered status field in a non-version descriptionI fall in deep-thought. So, I shutdown computer and restart it. I run sudo apt-get update and sudo apt-get install -f at terminal again. My ubuntu system fix-up its broken package list automatically.
E: Problem parsing dependency Replaces
E: Error occurred while processing gconf2-common (NewVersion1)
E: Problem with Mergelist /var/lib/dpkg/status
E: The package lists or status file could not be parsed or opened.
Now I can install my preferred software from software center again. I am very happy to get all thing normal.