It's been a while ago, and been dreading to experiment more. Since the kernel update from 4.4.0-128.154 to 4.4.0-130.156 it seems like Ubuntu does not recognize my graphics card. Sometimes on a restart it gives me graphics, but gives me this "Gone into low graphics mode, please reconfigure or troubleshoot" and I cannot proceed to a desktop. Other times I just get a blinking cursor on a black screen and sometimes in that state I can jump to another tty. Most the screen will clear, give me a few lines of startup logs, then blink several times as it tries to launch the login screen (lightdm). After it has blinked (assuming it does stop blinking) I can go into another tty. However, going back to 4.4.0-128.154 and having nvidia-384.130 installed it all runs fine (assuming I just shutdown without making changes).
With that said, when I've felt like trying to make 4.4.0-130.156 or higher work I have gone into a tty or recovery mode and tried a multitude of things I have found on the internet like dpkg-reconfigure, dpkg --configure, purged and reinstalled nvidia (current or specific number), going up from 384.130 to 387.26 and back again, purged and reinstalled lightdm, going back to 4.4.0-128.154 and setting proprietary drivers to X.Org X server, you name it. Each restart gives me one of the above results. And yes, I do get problems in 4.4.0-128.154 should I, say, remove nvidia all together.
Also, the few times when it does give me the "Low graphics mode" dialog box, whenever I try clicking reconfigure it just blinks and doesn't seem to do anything. When I choose the option to "Edit configuration file", the text-editor is blank.
This is the Xorg.0.log that I cpd over after reviewing the log from "Low graphics mode": https://pastebin.com/WtYsQ4Dm
This is the results from glxinfo that I ran today from a working 4.4.0-128.154 kernel and lightdm: https://pastebin.com/j3CXu6uc
Current Graphics Card: GeForce GTX 960/PCIe/SSE2 (GM206)
Any ideas what might be the problem here? Any other info-commands you want me to paste here?
EDIT The update to 4.4.0-133.139 has arrived, still the same problem. I have also been prompted to go up to 18.04 LTS, but I don't want to go there just yet and risk not getting back to the so far stable 4.4.0-128.
EDIT Well, Ubuntu decided to remove the 128 kernel forcing me to use the recent, and of course NVIDIA refused to launch which meant no Desktop. I practically just gave up and decided to do-release-upgrade to 18.04 (4.15.0-38). After a night of answering keep or discard questions and rebooting, the Desktop (lightdm) still did not open. After some searches I saw one could get drivers from the official Nvidia site, so I purged anything nvidia* related, and installed NVIDIA-Linux-x86_64-410.66.run. That got me a Desktop. However, I did a test with Blender (2.79) and there was no GPU support. Installed nvidia-modprobe to get the CUDA, rebooted, and still Blender did not have GPU support.
Going to System Tools -> Administration -> Software Update -> Settings (once displayed) -> Additional Drivers I found 3 options: Nvidia 390, nouveau, and a checked Configuration Set Manually. I assumed this was the Nvidia 410 that I installed. I decided to install nvidia-drivers-390 on top of 410, then purged, then apt-get install nvidia-drivers-390 nvidia-modprobe nvidia-cuda-toolkit all in one, rebooted, and tried Blender again. Still no GPU support.
Kinda considering to return this to the backup I have, upgrade to the 128 kernel, then disable all updates unless I get all functionality back.
