I'm not sure if the fault of the bug but I am sure that after you install bumblebee, primus and related 32bit versions optirun is identical normal startup applications EXAMPLE: With the integrated card of firefox you see as the lines when I watch videos on youtube, with optirun you still see the same amount alleged bug: libdrm-intel1 4.2.58 not allow you to switch between the video cards I hope everything is something temporary and resolved as soon as possible sorry for my English