Thanks for the bug report. It appears you no longer have an nvidia kernel driver for the current kernel version. I'm also not sure if such a newer kernel can be supported by the old nvidia 390 driver.
This might just be bug 1975650 so please try reinstalling the driver using the 'Additional Drivers' app or:
sudo apt install --reinstall nvidia-driver-390
and reboot. If reinstalling the driver doesn't solve the problem then I wonder if nvidia-390 requires sticking to an older kernel?
Thanks for the bug report. It appears you no longer have an nvidia kernel driver for the current kernel version. I'm also not sure if such a newer kernel can be supported by the old nvidia 390 driver.
This might just be bug 1975650 so please try reinstalling the driver using the 'Additional Drivers' app or:
sudo apt install --reinstall nvidia-driver-390
and reboot. If reinstalling the driver doesn't solve the problem then I wonder if nvidia-390 requires sticking to an older kernel?