The problem is not PAE, the problem is that the kernel parameters parser was changed as a result of the systemd debug params controversy.
You need to repeat the 'forcepae' twice in the linux kernel parameters, before and after the -- i.e.: linux ... forcepae -- forcepae Kernel patch that changed the previous behaviour was: commit 51e158c Author: Rusty Russell <ru...@rustcorp.com.au> Date: Mon Apr 28 11:34:33 2014 +0930 param: hand arguments after -- straight to init The kernel parses parameters from the kernel command line up to "--"; if it doesn't recognize a parameter and it doesn't contain a '.', the parameter gets passed to init: parameters with '=' go into init's environment, others are passed as command line arguments to init. Everything after "--" is passed as an argument to init. With "forcepae -- forcepae" I did a full install of the Vivid ISO link above. It worked ok. (There was a non-related bug, Ubuntu/grub puts "vt.handoff=7" in grub.cfg which causes a black screen on boot - looks like bug #913731 or some related regression). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1422675 Title: No installable kernel was found in the defined APT sources To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1422675/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs