We are going to need some more info. Can you please copy and paste the output of uname -srm
Can you also please attach the output of lspci -vvnn Finally, please attach the output of xrandr --verbose when the monitor does not work after booting with it connected and also when it does work after hotplugging it. ** Changed in: unity (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1284767 Title: Unity fails to start with a 4K monitor attached To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/1284767/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs