Ubuntu cannot boot correctly after Windows 10 updating

[ruwan2]

Hello,

I have my Lenovo Legion T5 desktop dual boot with Ubuntu 20.04 LTS on its SSD M.2 drive (256 GB). In the past, most of time I used Ubuntu, not Windows 10. A few weeks ago, I went to Windows 10 OS and it was installed new MSFT updates automatically. After the Windows 10 updates, reboot it, the screen showed:

"Failed to open \EFI\UBUNTU\Failed to load image \EFI\UBUNTU\start_image() returned Invalid Parameter, failing back to default loader"



Then, the GRUB screen showed menu options in larger fonts. Ubuntu can boot up, but very slowly than before and in low display resolution mode. The Legion has a low end PCIe Nvidia card installed.

Can you help me what is wrong? How can I make the Ubuntu system go back to normal?

Thanks in advance

[ruwan2]

Here is more info on this thread.

On the internet search, it looks like "Boot-Repair" tool could work on my case. The Ubuntu 20.04 LTS can still work, though it is in low display resolution. I install "Boot-Repair" sucessfully.
When I run the tool, it pops up this message:
"Please create a ESP partition (FAT32, 100MB-250MB, start of the disk, boot flag). This can be performed via tools such as Gparted. Then try again.

In Windows 10, hard drives are shown as:



Why does Boot-Repair want me to create a ESP partition?


Below are more info on the hard drives on this computer:












Thanks,

[grahammechanical]

On this forum we prefer users wanting help with booting to use Boot Repair to create a BootInfo summary and then add the pastebin address to the thread. We do not advise running Boot Repair to repair anything until some of us have seen for ourselves the situation on your machine from that BootInfo summary.

It is my understanding that a Windows update will usually put Windows fast startup back on and may even overwrite the information in the EFI boot partition and so erase the Ubuntu boot information in that partition. That could be the problem here.

As yet we do not know which drive and which partition Ubuntu is installed on. It is possible that the Ubuntu boot information was in the EFI partition of the drive that Windows is installed on. The EFI partition is large enough to hold boot information for more than one operating system and there will be no conflict. It is also possible that Boot Repair is programmed to look for a EFI partition on the drive that Ubuntu is installed on.

The solution may be to create the EFI partition and let boot repair put Ubuntu boot information into both EFI partitions and then when a Windows update overwrites the EFI boot information on the drive Windows is installed on you simply boot from the drive Ubuntu is installed on.

It seems that Ubuntu is loading in a low screen resolution mode. I suggest that it is best the fix the booting issue before asking why the normal video driver is not loading. We need to see the information in that Boot Repair summary. At this time we are just guessing.

Regards

[oldfred]

You may need to run chkdsk from Windows or dosfsck from Ubuntu on the ESP.
And/Or the Windows update also updated UEFI and reverted settings to defaults, review your UEFI settings.
Some systems have a way (??) to lock boot, some updates to UEFI turn UEFI Secure Boot back on.
And Windows updates often turn Windows fast start up back on.

While we need the Boot-Repair report, it will not show UEFI settings other than Secure Boot. You need to review those first.