I am getting same issue in ubuntu 14.04. I have installed nvidia 331 driver and when I switch to nvidia, it is throwing following error:
$ sudo prime-switch nvidia
/etc/modprobe.d is not a file
/etc/modprobe.d is not a file
/etc/modprobe.d is not a file
/etc/modprobe.d is not a file
update-alternatives: error: no alternatives for x86_64-linux-gnu_gfxcore_conf
I am getting same issue in ubuntu 14.04. I have installed nvidia 331 driver and when I switch to nvidia, it is throwing following error:
$ sudo prime-switch nvidia alternatives: error: no alternatives for x86_64- linux-gnu_ gfxcore_ conf
/etc/modprobe.d is not a file
/etc/modprobe.d is not a file
/etc/modprobe.d is not a file
/etc/modprobe.d is not a file
update-