After rebooting my Ubuntu 14.04 machine, I could not log into Unity again and I had to fall back on Gnome. I discovered that there is something wrong with GLX since when I run:/usr/lib/nux/unity_support_test -pI get the following message:Error: GLX is not available on the systemAlso, (relevant parts of) the output of less /var/log/Xorg.0.log looks like this:[   682.533] (II) LoadModule: glx[   682.533] (II) Loading /usr/lib/x86_64-linux-gnu/xorg/extra-modules/libglx.so[   682.533] (EE) Failed to load /usr/lib/x86_64-linux-gnu/xorg/extra-modules/libglx.so: libnvidia-tls.so.349.16: cannot open shared object file: No such file or directory[   682.533] (II) UnloadModule: glx[   682.533] (II) Unloading glx[   682.533] (EE) Failed to load module glx (loader failed, 7)[   682.533] (==) Matched nvidia as autoconfigured driver 0[   682.533] (==) Matched nouveau as autoconfigured driver 1[   682.533] (==) Matched nvidia as autoconfigured driver 2[   682.533] (==) Matched nouveau as autoconfigured driver 3[   682.533] (==) Matched modesetting as autoconfigured driver 4[   682.533] (==) Matched fbdev as autoconfigured driver 5[   682.533] (==) Matched vesa as autoconfigured driver 6[   682.533] (==) Assigned the driver to the xf86ConfigLayout[   682.533] (II) LoadModule: nvidia[   682.533] (II) Loading /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so[   682.534] (II) Module nvidia: vendor=NVIDIA Corporation[   682.534]     compiled for 4.0.2, module version = 1.0.0[   682.534]     Module class: X.Org Video Driver[   682.534] (II) LoadModule: nouveau[   682.534] (WW) Warning, couldn't open module nouveau[   682.534] (II) UnloadModule: nouveau[   682.534] (II) Unloading nouveau[   682.534] (EE) Failed to load module nouveau (module does not exist, 0)[   682.534] (II) LoadModule: modesetting[   682.534] (WW) Warning, couldn't open module modesetting[   682.534] (II) UnloadModule: modesetting[   682.534] (II) Unloading modesetting[   682.534] (EE) Failed to load module modesetting (module does not exist, 0)[   682.534] (II) LoadModule: fbdev[   682.534] (WW) Warning, couldn't open module fbdev[   682.534] (II) UnloadModule: fbdev[   682.534] (II) Unloading fbdev[   682.534] (EE) Failed to load module fbdev (module does not exist, 0)[   682.534] (II) LoadModule: vesa[   682.534] (WW) Warning, couldn't open module vesa[   682.534] (II) UnloadModule: vesa[   682.534] (II) Unloading vesa[   682.534] (EE) Failed to load module vesa (module does not exist, 0)[   682.534] (==) Matched nvidia as autoconfigured driver 0[   682.534] (==) Matched nouveau as autoconfigured driver 1[   682.534] (==) Matched nvidia as autoconfigured driver 2[   682.534] (==) Matched nouveau as autoconfigured driver 3[   682.534] (==) Matched modesetting as autoconfigured driver 4[   682.534] (==) Matched fbdev as autoconfigured driver 5[   682.534] (==) Matched vesa as autoconfigured driver 6[   682.534] (==) Assigned the driver to the xf86ConfigLayout[   682.534] (II) LoadModule: nvidia[   682.534] (II) Loading /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so[   682.534] (II) Module nvidia: vendor=NVIDIA Corporation[   682.534]     compiled for 4.0.2, module version = 1.0.0[   682.534]     Module class: X.Org Video Driver[   682.534] (II) UnloadModule: nvidia[   682.534] (II) Unloading nvidia[   682.534] (II) Failed to load module nvidia (already loaded, 32523)[   682.534] (II) LoadModule: nouveau[   682.534] (WW) Warning, couldn't open module nouveau[   682.534] (II) UnloadModule: nouveau[   682.534] (II) Unloading nouveau[   682.534] (EE) Failed to load module nouveau (module does not exist, 0)[   682.534] (II) LoadModule: modesetting[   682.535] (WW) Warning, couldn't open module modesetting[   682.535] (II) UnloadModule: modesetting[   682.535] (II) Unloading modesetting[   682.535] (EE) Failed to load module modesetting (module does not exist, 0)[   682.535] (II) LoadModule: fbdev[   682.535] (WW) Warning, couldn't open module fbdev[   682.535] (II) UnloadModule: fbdev[   682.535] (II) Unloading fbdev[   682.535] (EE) Failed to load module fbdev (module does not exist, 0)[   682.535] (II) LoadModule: vesa[   682.535] (WW) Warning, couldn't open module vesa[   682.535] (II) UnloadModule: vesa[   682.535] (II) Unloading vesa[   682.535] (EE) Failed to load module vesa (module does not exist, 0)[   682.535] (II) NVIDIA dlloader X Driver  349.16  Tue Apr  7 23:19:49 PDT 2015[   682.535] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs[   682.535] (++) using VT number 7[   682.539] (II) Loading sub module fb[   682.539] (II) LoadModule: fb[   682.539] (II) Loading /usr/lib/xorg/modules/libfb.so[   682.540] (II) Module fb: vendor=X.Org Foundation[   682.540]     compiled for 1.15.1, module version = 1.0.0[   682.540]     ABI class: X.Org ANSI C Emulation, version 0.4[   682.540] (II) Loading sub module wfb[   682.540] (II) LoadModule: wfb[   682.540] (II) Loading /usr/lib/xorg/modules/libwfb.so[   682.540] (II) Module wfb: vendor=X.Org Foundation[   682.540]     compiled for 1.15.1, module version = 1.0.0[   682.540]     ABI class: X.Org ANSI C Emulation, version 0.4[   682.540] (II) Loading sub module ramdac[   682.540] (II) LoadModule: ramdac[   682.540] (II) Module ramdac already built-in[   682.540] (II) NVIDIA(0): Creating default Display subsection in Screen section    Default Screen Section for depth/fbbpp 24/32[   682.540] (==) NVIDIA(0): Depth 24, (==) framebuffer bpp 32[   682.540] (==) NVIDIA(0): RGB weight 888[   682.540] (==) NVIDIA(0): Default visual is TrueColor[   682.540] (==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)[   682.540] (**) NVIDIA(0): Enabling 2D acceleration[   682.540] (EE) NVIDIA(0): Failed to initialize the GLX module; please check in your X[   682.540] (EE) NVIDIA(0):     log file that the GLX module has been loaded in your X[   682.540] (EE) NVIDIA(0):     server, and that the module is the NVIDIA GLX module.  If[   682.540] (EE) NVIDIA(0):     you continue to encounter problems, Please try[   682.540] (EE) NVIDIA(0):     reinstalling the NVIDIA driver.[   682.549] (II) NVIDIA(GPU-0): Found DRM driver nvidia-drm (20150116)[   682.550] (II) NVIDIA(0): NVIDIA GPU Quadro K2200 (GM107GL-A) at PCI:3:0:0 (GPU-0)[   682.550] (--) NVIDIA(0): Memory: 4194304 kBytes[   682.550] (--) NVIDIA(0): VideoBIOS: 82.07.5a.00.01[   682.550] (II) NVIDIA(0): Detected PCI Express Link width: 16X[   682.622] (--) NVIDIA(0): Valid display device(s) on Quadro K2200 at PCI:3:0:0[   682.622] (--) NVIDIA(0):     CRT-0[   682.622] (--) NVIDIA(0):     DFP-0[   682.622] (--) NVIDIA(0):     DFP-1[   682.622] (--) NVIDIA(0):     DFP-2[   682.622] (--) NVIDIA(0):     DELL U2711 (DFP-3) (connected)[   682.622] (--) NVIDIA(0):     DELL 2709W (DFP-4) (boot, connected)[   682.622] (--) NVIDIA(GPU-0): CRT-0: 400.0 MHz maximum pixel clock[   682.622] (--) NVIDIA(0): DFP-0: Internal TMDS[   682.622] (--) NVIDIA(GPU-0): DFP-0: 330.0 MHz maximum pixel clock[   682.622] (--) NVIDIA(0): DFP-1: Internal TMDS[   682.622] (--) NVIDIA(GPU-0): DFP-1: 165.0 MHz maximum pixel clock[   682.622] (--) NVIDIA(0): DFP-2: Internal TMDS[   682.622] (--) NVIDIA(GPU-0): DFP-2: 165.0 MHz maximum pixel clock[   682.622] (--) NVIDIA(0): DELL U2711 (DFP-3): Internal DisplayPort[   682.622] (--) NVIDIA(GPU-0): DELL U2711 (DFP-3): 960.0 MHz maximum pixel clock[   682.623] (--) NVIDIA(0): DELL 2709W (DFP-4): Internal DisplayPort[   682.623] (--) NVIDIA(GPU-0): DELL 2709W (DFP-4): 960.0 MHz maximum pixel clock[   682.623] (**) NVIDIA(0): Using HorizSync/VertRefresh ranges from the EDID for display[   682.623] (**) NVIDIA(0):     device DELL U2711 (DFP-3) (Using EDID frequencies has been[   682.623] (**) NVIDIA(0):     enabled on all display devices.)[   682.625] (**) NVIDIA(0): Using HorizSync/VertRefresh ranges from the EDID for display[   682.625] (**) NVIDIA(0):     device DELL 2709W (DFP-4) (Using EDID frequencies has been[   682.625] (**) NVIDIA(0):     enabled on all display devices.)[   682.642] (==) NVIDIA(0): [   682.642] (==) NVIDIA(0): No modes were requested; the default mode nvidia-auto-select[   682.642] (==) NVIDIA(0):     will be used as the requested mode.[   682.642] (==) NVIDIA(0): [   682.642] (II) NVIDIA(0): Validated MetaModes:[   682.642] (II) NVIDIA(0):     DFP-4:nvidia-auto-select,DFP-3:nvidia-auto-select[   682.642] (II) NVIDIA(0): Virtual screen size determined to be 4480 x 1440[   682.643] (--) NVIDIA(0): DPI set to (84, 84); computed from UseEdidDpi X config[   682.643] (--) NVIDIA(0):     option[   682.643] (--) Depth 24 pixmap format is 32 bpp[   682.644] (II) NVIDIA: Using 3072.00 MB of virtual memory for indirect memory[   682.644] (II) NVIDIA:     access.[   682.649] (II) NVIDIA(0): Setting mode DFP-4:nvidia-auto-select,DFP-3:nvidia-auto-select[   682.723] Loading extension NV-GLX[   682.769] (==) NVIDIA(0): Disabling shared memory pixmaps[   682.769] (==) NVIDIA(0): Backing store enabled[   682.769] (==) NVIDIA(0): Silken mouse enabled[   682.769] (==) NVIDIA(0): DPMS enabled[   682.769] Loading extension NV-CONTROL[   682.769] Loading extension XINERAMA[   682.769] (II) Loading sub module dri2[   682.769] (II) LoadModule: dri2[   682.769] (II) Module dri2 already built-in[   682.769] (II) NVIDIA(0): [DRI2] Setup complete[   682.769] (II) NVIDIA(0): [DRI2]   VDPAU driver: nvidiaI already tried re-installing the NVidia driver (346.82) and also tried with a newer version (355.06) but I couldn't solve the problem. Also, I'm not able to play any kind of video that I used to play without any problem.How can I make the GLX work correctly again?EDIT:Also, here is the output of glxinfo on terminal:Error: couldn't find RGB GLX visual or fbconfigI think this confirms GLX doesn't work. Also when I run nvidia-settings , under OpenGL/GLX Information, I see:Failed to query the GLX server vendor.
Error: GLX is not available on the system
nvidia;opengl;unity