Emergency boot, after fglrx

After installing fglrx then restarting, I was able to boot normally in the beginning.
I'm not sure. After changing rendering backend to OpenGL 3, I boot to emergency mode. To continue boot, I run: systemctl default. I returned it to OpenGL 2, but I still see emergency mode every boot.
Restart or power off returns me to emergency boot terminal, but it hangs (I can't write anything), so I press shutdown button to turn it off.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: fglrx 2:15.200-0ubuntu4
ProcVersionSignature: Ubuntu 3.19.0-21.21-generic 3.19.8
Uname: Linux 3.19.0-21-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: KDE
Date: Wed Jun 17 19:01:04 2015
InstallationDate: Installed on 2015-06-09 (7 days ago)
InstallationMedia: Kubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: fglrx-installer
UpgradeStatus: No upgrade log present (probably fresh install)