More googling suggests this has to do with using bumblebee to use the nvidia and intel GPUs. I used the following blog to install the nvidia drivers.
http://lenovolinux.blogspot.nl/2016/05/bumblebee-on-lenovo-t440p-nvidia- gt.html I can now use either GPU at my disposal: $ glxgears -info Running synchronized to the vertical refresh. The framerate should be approximately the same as the monitor refresh rate. GL_RENDERER = Mesa DRI Intel(R) HD Graphics 520 (Skylake GT2) GL_VERSION = 3.0 Mesa 11.2.0 GL_VENDOR = Intel Open Source Technology Center $ optirun glxgears -info GL_RENDERER = GeForce 940M/PCIe/SSE2 GL_VERSION = 4.5.0 NVIDIA 361.42 GL_VENDOR = NVIDIA Corporation -- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to kubuntu-meta in Ubuntu. https://bugs.launchpad.net/bugs/1577041 Title: Cannot login to kubuntu after upgrade To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kubuntu-meta/+bug/1577041/+subscriptions -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs
