The ubuntu-drivers script mistakenly parsing “open” as a int ( Solution discussed above)
The other is even when installed through the Additional Drivers tab or by fixing script, I ended up with a kernel panic with “Out of Memory … press any key to continue”. Where the only option was reboot and get to grub menu and choose a older kernel version. Then reverting to xorg nouveau driver.
For Issue 2 - Downgrading to nvidia driver 470 worked for me.