This question is an exact duplicate of:
Every time I try installing Software Center on Kali Linux 2.0. it says:
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: software-center : Depends: aptdaemon (>= 0.40) but it is not going to be installed Depends: python-gobject (>= 3.0) but it is not going to be installed Depends: python-gobject-cairo Depends: python-aptdaemon (>= 0.40) but it is not going to be installed Depends: python-aptdaemon.gtk3widgets but it is not going to be installed Recommends: gir1.2-launchpad-integration-3.0 but it is not installable Recommends: software-properties-gtk but it is not going to be installed Recommends: sessioninstaller but it is not installable E: Unable to correct problems, you have held broken packages.
What can I do to fix this?