Fixing Nvidia + Bumblebee + Dell L502X error in Ubuntu 16.04

For some weird reason the Ubuntu 16.04 Bumblebee’s default version was not being able to switch on/off my discrete video card NVIDIA Corporation GF108M [GeForce GT 540M]. I was getting the following error: $ optirun glxgears [ 7224.163607] [ERROR]Cannot access secondary GPU – error: [XORG] (EE) [ 7224.163722] [ERROR]Aborting because fallback start is disabled. I was able to solve the aforementioned issue in this way: 1) Adding the repository with fresh bumbleblee packages: $ sudo add-apt-repository ppa:bumblebee/testing 2) Updating the repositories and upgrade bumblebee: $ sudo apt-get update; sudo apt-get upgrade 3) Adjusting /etc/bumblebee/bumblebee.conf file: 4) Adjusting the /etc/bumblebee/xorg.conf-nvidia , […]