grub_file_filters not found after Ubuntu 19.10 upgrade

Question

I upgraded Ubuntu from 19.04 to 19.10. The upgrade went without errors but after restart grub throws an error on startup and goes into rescu mode

error: symbol 'grub_file_filters' not found. 
Entering rescue mode... 
grub rescue>

It's a physical machine not a virtualbox, and I have windows and linux in dual boot.

I managed to find what partition is my linux on with ls, but don't really know what to do next.

insmod normal fails with the same error

Solution 1

I had exactly the same problem about a week ago. I solved it by downloading the boot-repair-disk from sourceforge. You will need to manufacture a bootable USB key or CD if you have a suitable CD drive. There are plenty of guides online about how to do this. I hope you have access to a system where you can do it. You can do it on Windows.

It may be possible to fix it from the grub rescue prompt and then the grub prompt. I tried this first but didn’t have success following a guide I found online.

Good luck

Solution 2

In my case, I had an Xubuntu 18.04 VM and after upgrading to 20.04, got the grub error. So I followed what's described here, which is for Kali, but should work for any Linux / grub installation:

1. Using an Ubuntu / Xubuntu ISO Live enter live mode (I used Ubuntu 20.04 since I had it already downloaded in my computer).

2. Once inside, I opened a terminal and ran:

# So we can run the next commands as `root`:
sudo su

# To figure which partition had my Xubuntu installation (partition type `Linux`)
# in my case it was `/dev/sda1`, we can use:
fdisk -l
# If you used a logical volume, your volume should be named `/dev/mapper/ubuntu--vg-root` and not `/dev/sdxx`

# Let's mount a few things:
mount /dev/sda1 /mnt
mount --bind /dev /mnt/dev
mount --bind /dev/pts /mnt/dev/pts
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys

chroot /mnt

# Now let's try to fix Grub:
grub-install /dev/sda

If things went well, you should see a message saying something like:

Installation finished. No error reported

3. Now we can cleanup and reboot:

# To change back chroot:
exit

# And now we can umount all:
umount /mnt/dev/pts
umount /mnt/dev
umount /mnt/proc
umount /mnt/sys
umount /mnt

# Now we can reboot:
reboot

Solution 3

Got the same issue, fixed by booting a 19.10 "rescue" USB key then, in terminal: (where sda is your disk and sda1 is your partition on the disk.)

$ sudo mount /dev/sda1 /mnt
$ sudo grub-install --root-directory=/mnt /dev/sda

Note - if you have more than one physical disk, your BIOS may be looking on a different one. You may need to do this for each physical disk.

Solution 4

I couldn't get boot-repair (or boot-repair-disk) working, but managed to fix this by booting from a live Ubuntu 19.10 USB, mounting the old disk, entering chroot, and running grub-install and update-grub.

There is a launchpad bug here, which recommends the chroot fix as described here.

Solution 5

I too encountered the exact same problem after updating to Ubuntu 19.10. Here is how I (just now) resolved it:

First, you have two problems, not one. Both your installation is screwed up and the Grub Bootloader is messed up. And running only one fix won't fix everything. You need both the "boot-repair-disk" and the latest version of Ubuntu (both on USB boot drives. Don't use a DVD.)

If you try to do (only) a "Repair Install" from the Ubuntu Live disk first, you'll still be greeted by the "grub rescue>" prompt when done. :( So, first you must use the "boot-repair-disk". Tell it to repair your broken boot partition with Ubuntu on it. If you aren't sure of the partition ID, launch "GParted" from the "Start" menu (bottom left.)

Repair that boot partition. This should at least bring Grub back. Try to launch Ubuntu. If it works, you're done. If not, boot the Live "CD" from USB.

Double-click the "Install Ubuntu 19.10" icon on the desktop (don't worry, there will be an option to repair w/o losing your old programs/files.)

I recommend checking the boxes to download all updates during install, including 3rd party.

The Installer should detect your broken partition and give you the option to repair it (the first option.) It may need to disable some 3rd party repositories. Not a big deal, they're easy enough to get back later.

(Note: If you had to login with a password before, don't try to select "login w/o password" now. It won't let you in when you're done.)

Once done, you should have Ubuntu 19.10 installed with all/most of your existing apps still installed (though the toolbar shortcuts will be reset.) I had to reinstall a few 3rd party apps, but their configurations were still there afterwards, so nothing was lost.

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Comments

[nobody]

can you try to boot your system this way unix.stackexchange.com/questions/148041/…

[Eugene msc]

I tried it. Once I get to insmod command the same error pops up.

[nobody]

Have you an ubuntu live-session? And if so, are you familiar with to biuld a chroot?

[Eugene msc]

Sadly the answer is no to both your questions

[WinEunuuchs2Unix]

See: How to make grub menu appear instead grub minimal bash-like in booting?

[Blupon]

OP already has a solution but got a similar issue with a release upgrade 18.04-->20.04 on a 2 SSDs W10-Ubuntu dual boot: in addition to grub-install/update-grub to repair Ubuntu boot (cf. other answers; also starting from grub rescue), I had to convert MBR to GPT windowscentral.com/… (BIOS to UEFI) on my W10 SSD so that another update-grub could re-add W10 to the grub boot menu

[Eugene msc]

I only was able to fix this with a live usb stick an boot-reapair. as in WinEunuuchs2Unix's comment. Nothing I did in grub rescue worked

[mfnx]

thx. Did the same and it worked. I wrote the iso to a usb with a ubuntu session from a ubuntublive cd

[afosbenner]

I ran into this same problem when upgrading from Ubuntu 18.04 LTS to 20.04. Following the instructions in this answer worked perfectly for me using an Ubuntu 20.04 live flash drive.

[G_Style]

This one should be the answer. Grub just needs to be re-installed. If you get this error on a default Ubuntu upgrade from 18.04 to 20.04, boot off a live ubuntu USB stick, drop to a shell and type those commands. Fixed it for me in 3 mins.

[Bashar Al-Abdulhadi]

I also upgraded my ThinkPad W520 from 18.04 to 20.04 and fallen into the same problem. following the above (I had ubuntu 18.04 ISO) and it worked. Thank you and to the video

[Silvio Mayolo]

Nearly gave me a heart attack trying to upgrade Ubuntu 18.04 to 20.04 today, but all it took was a quick grub reinstall and it was up and running.

[karel]

duplicate of the accepted answer

[MadPhysicist]

I second that this fixed me up during an upgrade from Ubuntu 18 to 20.

[Anne Gunn]

Worked for me after upgrade from Ubuntu 16 to 20. Saved my afternoon. Thanks!

[Bram]

If I do info grub-install I see no such option of root-directory, but there is a boot-directory option. Are you sure this info is correct?

[Bram]

I have an efi boot partition, do I need an extra mount in this procedure?

[Admin]

If you get error about blocklists try using --force option