This is because of packages you've installed from the xorg-edgers PPA. The web page for their PPA contains details regarding how to uninstall their versions of packages and install Ubuntu's. After you've installed Ubuntu's version of the packages, you'll be able to complete the upgrade.
This is because of packages you've installed from the xorg-edgers PPA. The web page for their PPA contains details regarding how to uninstall their versions of packages and install Ubuntu's. After you've installed Ubuntu's version of the packages, you'll be able to complete the upgrade.