Unable to switch to Nvidia (performance mode) in Nvidia Settings

[Nekhelesh Ramananthan]

After a recent update to Nvidia-331, I am no longer able to switch to the Nvidia (performance mode) through the Nvidia X Server Settings applications. When I try switching I get a warning dialog box with no text which makes it impossible to understand why it doesn't happen. I have attached a screenshot of the dialog that I see.

FYI this issue was not present until the nvidia-331 package update 2-3 days ago.

I have tried purging and then reinstalling Nvida-331-updates and nvidia-prime but still have the issue.

Here are the following information,
Ubuntu 14.04 (upgraded from saucy 13.10 few days ago)
Lenovo Y510P Nvidia GeForce 755M

nvidia-331-updates: Installed: 331.38-0ubuntu4
nvidia-prime: Installed: 0.6
nvidia-settings: Installed: 331.20-0ubuntu8

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: nvidia-331-updates 331.38-0ubuntu4
ProcVersionSignature: Ubuntu 3.13.0-16.36-generic 3.13.5
Uname: Linux 3.13.0-16-generic x86_64
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Sat Mar 8 22:01:23 2014
InstallationDate: Installed on 2013-09-18 (171 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130802)
SourcePackage: nvidia-graphics-drivers-331-updates
UpgradeStatus: Upgraded to trusty on 2014-02-27 (9 days ago)
modified.conffile..etc.modprobe.d.nvidia.331.updates.hybrid.conf: [deleted]

[Nekhelesh Ramananthan (nik90)]

On running Nvidia Settings through the terminal, here is output I got,

krnekhelesh@nik90-lenovo-ubuntu:~$ nvidia-settings
** Message: PRIME: Laptop detected
** Message: PRIME: is it supported? yes

ERROR:

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.