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I upgraded to Ubuntu 15.04 which was just released. After reboot, I get as far as the login screen but it only appears for a second, then it goes to an infinite loop of screen flickering. How could I fix it?

Here is a video of what I'm seeing: https://youtu.be/NCtCw267v8Y

(The tag "Nvidia" is added to this question as that is, or at least was, my graphics driver.)

Note that switching to upstart does not fix this, nor am I able to enter the command line with ctrl+alt+f2.

Update: when I boot with recovery mode, /var/log/Xorg.0.log is empty, and I can at least enter my password (which in normal mode is impossible) but then it starts the same flickering, see this second video recording: https://youtu.be/AdOqBKPnUKA

Valid workaround: go to recovery mode, open a root shell, get list of relevant packages with dpkg -l | grep -i nvidia and remove them all with apt-get remove --purge [package] (for me, they were versions 340 and 331 while the one nvidia itself recommends me - 350 - is not in any ubuntu package)

Solution: upgrade your kernel like this.

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Gabor
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  • Possible duplicate http://askubuntu.com/questions/613009/impossible-to-boot-after-proprietary-drivers-installation-nvidia – Velkan Apr 24 '15 at 21:34
  • It is definitely not a duplicate of that one, but if you have an answer, would be happy to hear it. – Gabor Apr 24 '15 at 21:44
  • What card do you have? Because I've got nv 760 and now I'm not so sure if it's safe to upgrade to 15.04 developer release. There is too much activity on askubuntu regarding the breakage of Nvidia proprietary driver after the update. – Velkan Apr 26 '15 at 12:23
  • I've got a GeForce GT 620M, by the way 15.04 has been an official release when I got promted about the upgrade – Gabor Apr 28 '15 at 07:59
  • May be it's a good time to give the nouveau driver a try ? – solsTiCe Apr 28 '15 at 22:03

2 Answers2

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I had a similar issue where the normal boot sequence got into a repeated failure pattern like your posted video shows. To be sure you can look at the log file /var/log/Xorg.0.log. In my case, I was able to boot into recovery mode, drop to a root shell, then install a different nvidia driver. In my case, nvidia-340 was installed after the upgrade to 15.04, and upgrading to nvidia-346 fixed it.

In case it helps, here are the steps I followed to fix this.
Problem booting after updating from Ubuntu 14.10 to 15.04

Good luck.

Dennis

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dennisobrien
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Until some easier procedure comes along for a noob such as myself, I reverted to the Noveaux driver, Nvidia 340.76 just makes Ubuntu 15.04 unstable.

Dom Fel
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  • Did you try to upgrade your kernel as I suggested in the "Solution" above? It solved the issue for me, and is very simple and fast to do. – Gabor Jun 06 '15 at 08:57