No EDID is found for your monitor (and the hardware doesn't report any errors when trying to retrieve it). So you have to add the modes manually (xorg.conf or with xrandr, or maybe there is a gui option by now?) or pass a fake EDID to use.
** Changed in: xserver-xorg-video-intel (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1272621 Title: Resolution higher than 1024×768 for Acer x233h external monitor is not available To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1272621/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs