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:
 libreoffice : Depends: libreoffice-base but it is not going to be installed
               Depends: libreoffice-calc but it is not going to be installed
               Depends: libreoffice-core (= 1:4.2.8-0ubuntu4) but it is not going to be installed
               Depends: libreoffice-draw but it is not going to be installed
               Depends: libreoffice-impress but it is not going to be installed
               Depends: libreoffice-math but it is not going to be installed
               Depends: libreoffice-report-builder-bin but it is not going to be installed
               Depends: libreoffice-writer but it is not going to be installed
               Depends: libreoffice-avmedia-backend-gstreamer but it is not going to be installed
               Depends: python3-uno (>= 4.0~) but it is not going to be installed
               Recommends: libreoffice-gnome but it is not going to be installed or
                           libreoffice-kde but it is not going to be installed
E: Unable to correct problems, you have held broken packages.