I just updated my backup system (18.04.3) and my display (1920x1080) went into 800x600 mode and I am unable to correct. In the control panel the display shows as unknown and I can't change any settings. It has an Nvidia Quadro 600 graphics card.
I booted into Clear Linux and Ubuntu on other drives and everything was fine. I changed the Quadro out with a Radeon RX 460, booted into the original UM disk and everything was back to normal.
I installed Ubuntu Mate 18.04.3 onto a different drive. The installation program looked fine (I checked the box to install updates during the installation). When I rebooted to the fresh installation, I had the same 800x600 problem.
Is there something recent with UM that has changed to cause this problem with Nvidia? Is there something with the configuration I can try? All of my other machines with UM aren't experiencing this (none have Nvidia graphics). I keep my back up machine up to date, roughly weekly so this seems to be recent.
There was a an update to the HWE this week that updated the kernel to a 5.3x kernel.
Can you run the following and give us the output: uname -a
In addition can you open Software & Updates click on the Additional Drivers tab and take a screen shot of that and upload that here. You can take a screenshot of the open windows using alt + PrtScn
Doing more research shows that it was indeed the kernel update. I went into Advanced options at the grub start up screen (ESC key) and chose the 5.0 kernel and everything seems normal.
There's also a discussion on the Linux Mint forum with some suggestions for solving the problem. I was able to get it to work with the new kernel on my Ubuntu disk though there are warnings and errors. I'm not sure how I got there as the suggestions didn't seem to work so I just tried variations of what they were doing, and as I was about to give up, it worked (don't really care if the installation gets hosed since it's on a spare disk). It seems there's an update to the 390 driver but didn't make it to the normal update/upgrade process.
I don't want to mess with my U-Mate disk for now and I'll wait to see if it gets corrected as I'm not the only one that is effected.
The good is I took an older drive with the 5.0 kernel and updated it. All worked well. This is good as I volunteer for a "not for profit" organization and had installed UM on the PC they use which has almost identical specs as the machine I have. So I can just update it without worry.
The bad is the drive that was on my backup machine had broken dependencies and wouldn't update. I tried the suggestions that apt gave me (fix broken something, apt install -f), but it didn't help. I'm sure there is a way through the command line but the knowledge level is beyond me. So I did a fresh install. As I was using it as a back up machine, not a big deal except for setting it up the way I like it. Funny how all those little tweaks through the years add up.
