nvidia-346 prime alternatives not set up properly

[fcole90]

I just installed the nvidia-346 drivers with all its dependencies. I then rebooted twice (the very first reboot started to load the system and went back to grub, so I removed the 'quiet' string from the loader to check what happened, I noted that some nouveau libraries were loaded, is it normal?). When trying to use prime-select query it says unknown, and if I try any between intel and nvidia it says that:
Error: alternatives are not set up properly
Error: intel mode can't be enabled

or

Error: alternatives are not set up properly
Error: nvidia mode can't be enabled

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: nvidia-346 346.82-0ubuntu0.2
ProcVersionSignature: Ubuntu 3.19.0-26.28~14.04.1-generic 3.19.8-ckt4
Uname: Linux 3.19.0-26-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.12
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Aug 25 08:41:02 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-03-21 (156 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
SourcePackage: nvidia-graphics-drivers-346
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.modprobe.d.nvidia.346.hybrid.conf: [deleted]