Unable to boot ubuntu and falling to shell / "Missing Modules" and "UUID does not exist" after a forced update on Windows partition / DUAL Boot

granito2526 · March 3, 2026, 10:59am

Ubuntu Version:
Example: 22.04 LTS, 24.04, 25.10
Win Version:
auto upgrade from 10 to 11

I ran my ACER laptop with Windows alongside my Ubuntu (one harddrive) perfectly until Windows forced an update.

Now Ubuntu isnt able to boot and falling back to BusyBox shell as follows:

"

Gave up waiting for root file system device. Common problems:

- Boot args (cat /proc/cmdline)

- Check rootdelay= (..)

- Missing modules (cat /proc/modules; ls /dev)

ALERT! UUID=XX does not exist. Dropping to a shell!

"

I assume this is a rather quick fix for advanced users but too hard for me Help is much much appreciated since I need to access my data rather urgently.

Many thanks in advance.

Edit:

Both Win and Ubuntu run in UEFI mode.

Set the Intel VMD (Volume Management Device) option to ‘disabled’.

I deactivated Hybernate / Fast boot in Windows.

Still falling to shell while booting Ubuntu.

In accordance to user comment I added the output of sudo blkid and lsblk -f -o +partuuid

.After that there is the report from boot-repair via live session.

```

sudo blkid

/dev/sda1: BLOCK_SIZE=“2048” UUID=“2024-08-27-16-23-26-00” LABEL=“Ubuntu 24.04.1 LTS amd64” TYPE=“iso9660” PARTLABEL=“ISO9660” PARTUUID=“eed3de8a-acd3-4541-ba14-9014c007d874”

/dev/loop1: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop2: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop0: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/sda4: LABEL=“writable” UUID=“7ba8f5eb-459c-4775-81b1-5eb96208e392” BLOCK_SIZE=“4096” TYPE=“ext4” PARTUUID=“1ba88122-8cb4-4515-9ad6-af24d7c251fe”

/dev/sda2: SEC_TYPE=“msdos” LABEL_FATBOOT=“ESP” LABEL=“ESP” UUID=“3C53-CAEB” BLOCK_SIZE=“512” TYPE=“vfat” PARTLABEL=“Appended2” PARTUUID=“eed3de8a-acd3-4541-ba17-9014c007d874”

/dev/nvme0n1: PTUUID=“3c18016c-6841-4b50-97e2-4485ca4261e2” PTTYPE=“gpt”

/dev/loop8: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop6: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop13: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop4: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop11: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop9: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop7: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/sda3: PARTLABEL=“Gap1” PARTUUID=“eed3de8a-acd3-4541-ba16-9014c007d874”

/dev/loop5: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop12: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop3: BLOCK_SIZE=“131072” TYPE=“squashfs”

/dev/loop10: BLOCK_SIZE=“131072” TYPE=“squashfs”

lsblk -f -o +partuuid

NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS PARTUUID

loop0

squash 4.0 0 100% /rofs

loop1

squash 4.0

loop2

squash 4.0

loop3

squash 4.0 0 100% /snap/core22/1564

loop4

squash 4.0 0 100% /snap/firefox/4793

loop5

squash 4.0 0 100% /snap/bare/5

loop6

squash 4.0 0 100% /snap/gnome-42-2204/176

loop7

squash 4.0 0 100% /snap/firmware-updater/127

loop8

squash 4.0 0 100% /snap/thunderbird/507

loop9

squash 4.0 0 100% /snap/ubuntu-desktop-bootstrap/237

loop10

squash 4.0 0 100% /snap/snap-store/1173

loop11

squash 4.0 0 100% /snap/snapd-desktop-integration/178

loop12

squash 4.0 0 100% /snap/snapd/21759

loop13

squash 4.0 0 100% /snap/gtk-common-themes/1535

sda iso966 Jolie Ubuntu 24.04.1 LTS amd64 2024-08-27-16-23-26-00

├─sda1

│ iso966 Jolie Ubuntu 24.04.1 LTS amd64 2024-08-27-16-23-26-00 0 100% /cdrom eed3de8a-acd3-4541-ba14-9014c007d874

├─sda2

│ vfat FAT12 ESP 3C53-CAEB eed3de8a-acd3-4541-ba17-9014c007d874

├─sda3

│ eed3de8a-acd3-4541-ba16-9014c007d874

└─sda4

ext4 1.0 writable 7ba8f5eb-459c-4775-81b1-5eb96208e392 48.2G 0% /var/crash 1ba88122-8cb4-4515-9ad6-af24d7c251fe

/var/log

nvme0n1

boot-repair-4ppa2088 [20260301_1528]

============================== Boot Info Summary ===============================

=> No boot loader is installed in the MBR of /dev/nvme0n1.

nvme0n1p1: _____________________________________________________________________

File system:

Boot sector type: Unknown

Boot sector info:

nvme0n1p2: _____________________________________________________________________

File system:

Boot sector type: Unknown

Boot sector info:

nvme0n1p3: _____________________________________________________________________

File system:

Boot sector type: Unknown

Boot sector info:

nvme0n1p4: _____________________________________________________________________

File system:

Boot sector type: Unknown

Boot sector info:

sda: ___________________________________________________________________________

File system: iso9660

Boot sector type: Grub2 (v1.99-2.00)

Boot sector info: Grub2 (v1.99-2.00) is installed in the boot sector of

sda and looks at sector 0 of the same hard drive for

core.img, but core.img can not be found at this

location.

Mounting failed: mount: /mnt/BootInfo/FD/sda: /dev/sda already mounted or mount point busy.

dmesg(1) may have more information after failed mount system call.

================================ 0 OS detected =================================

================================ Host/Hardware =================================

CPU architecture: 64-bit

Video: Alder Lake-P GT1 [UHD Graphics] from Intel Corporation

Live-session OS is Ubuntu 64-bit (Ubuntu 24.04.1 LTS, noble, x86_64)

===================================== UEFI =====================================

BIOS/UEFI firmware: V1.27(1.27) from Insyde Corp.

The firmware is EFI-compatible, and is set in EFI-mode for this live-session.

SecureBoot disabled (confirmed by mokutil).

BootCurrent: 0000

Timeout: 0 seconds

BootOrder: 0000,0001,0002,2001,2002,2003

Boot0000* Linpus lite HD(2,GPT,eed3de8a-acd3-4541-ba17-9014c007d874,0xb8b5a0,0x27a0)/File(\EFI\Boot\grubx64.efi)RC

Boot0001* Windows Boot Manager HD(1,GPT,c765804e-bb9d-441f-baf6-d3e9de1d12ae,0x800,0x219800)/File(\EFI\Microsoft\Boot\bootmgfw.efi)57494e444f5753000100000088000000780000004200430044004f0042004a004500430054003d007b00390064006500610038003600320063002d0035006300640064002d0034006500370030002d0061006300630031002d006600330032006200330034003400640034003700390035007d00000000000100000010000000040000007fff0400

Boot0002* ubuntu HD(1,GPT,c765804e-bb9d-441f-baf6-d3e9de1d12ae,0x800,0x219800)/File(\EFI\ubuntu\shimx64.efi)

Boot2001* EFI USB Device RC

Boot2002* EFI DVD/CDROM RC

Boot2003* EFI Network RC

============================= Drive/Partition Info =============================

Disks info: ____________________________________________________________________

Partitions info (1/3): _________________________________________________________

Partitions info (2/3): _________________________________________________________

Partitions info (3/3): _________________________________________________________

fdisk -l (filtered): ___________________________________________________________

Disk nvme0n1: 476.94 GiB, 512110190592 bytes, 1000215216 sectors

Disk identifier: 3C18016C-6841-4B50-97E2-4485CA4261E2

Start End Sectors Size Type

nvme0n1p1 2048 2203647 2201600 1G EFI System

nvme0n1p2 2203648 510017535 507813888 242.1G Linux filesystem

nvme0n1p3 510017536 510050303 32768 16M Microsoft reserved

nvme0n1p4 510050304 998334463 488284160 232.8G Microsoft basic data

nvme0n1p5 998334464 1000212479 1878016 917M Windows recovery environment

Disk sda: 57.71 GiB, 61964550144 bytes, 121024512 sectors

Disk identifier: EED3DE8A-ACD3-4541-BA15-9014C007D874

Start End Sectors Size Type

sda1 64 12105119 12105056 5.8G Microsoft basic data

sda2 12105120 12115263 10144 5M EFI System

sda3 12115264 12115863 600 300K Microsoft basic data

sda4 12115968 121022463 108906496 51.9G Linux filesystem

parted -lm (filtered): _________________________________________________________

sda:62.0GB:scsi:512:512:gpt: USB SanDisk 3.2Gen1:;

1:32.8kB:6198MB:6198MB::ISO9660:hidden, msftdata;

2:6198MB:6203MB:5194kB::Appended2:boot, esp;

3:6203MB:6203MB:307kB::Gap1:hidden, msftdata;

4:6203MB:62.0GB:55.8GB:ext4::;

nvme0n1:512GB:nvme:512:512:gpt:Micron_2450_MTFDKBA512TFK:;

1:1049kB:1128MB:1127MB:fat32::boot, esp;

2:1128MB:261GB:260GB:ext4::;

3:261GB:261GB:16.8MB::Microsoft reserved partition:msftres, no_automount;

4:261GB:511GB:250GB:ntfs:Basic data partition:msftdata;

5:511GB:512GB:962MB:ntfs::hidden, diag, no_automount;

blkid (filtered): ______________________________________________________________

NAME FSTYPE UUID PARTUUID LABEL PARTLABEL

sda iso9660 2024-08-27-16-23-26-00 Ubuntu 24.04.1 LTS amd64

├─sda1 iso9660 2024-08-27-16-23-26-00 eed3de8a-acd3-4541-ba14-9014c007d874 Ubuntu 24.04.1 LTS amd64 ISO9660

├─sda2 vfat 3C53-CAEB eed3de8a-acd3-4541-ba17-9014c007d874 ESP Appended2

├─sda3 eed3de8a-acd3-4541-ba16-9014c007d874 Gap1

└─sda4 ext4 7ba8f5eb-459c-4775-81b1-5eb96208e392 1ba88122-8cb4-4515-9ad6-af24d7c251fe writable

nvme0n1

Mount points (filtered): _______________________________________________________

Avail Use% Mounted on

/dev/sda1 0 100% /cdrom

efivarfs 76.2K 70% /sys/firmware/efi/efivars

Mount options (filtered): ______________________________________________________

/dev/sda1 iso9660 ro,noatime,nojoliet,check=s,map=n,blocksize=2048,iocharset=utf8

======================== Unknown MBRs/Boot Sectors/etc =========================

/dev/nvme0n1p3: unknown GPT attributes

8000000000000000

Unknown BootLoader on nvme0n1p1

Unknown BootLoader on nvme0n1p2

Unknown BootLoader on nvme0n1p3

Unknown BootLoader on nvme0n1p4

Suggested repair: ______________________________________________________________

The default repair of the Boot-Repair utility would not act on the boot.

```

yancek · March 3, 2026, 12:56pm

ALERT UUID check the actual UUID and compare it to the output of sudo blkid for partition 2 on the SSC
When you select Ubuntu from the BIOS option shown, do you get this errror?
Disabled fast boot and hibernate, is bitlocker on?
When you run boot repair with Create BootInfo Summary option, it gives you a link to post here and you should not copy it.
The loop output is meaningless in this scenario as is the output referencing sda as that is the Ubuntu usb.

granito2526 · March 3, 2026, 2:09pm

Hello Yancek and thanks a lot for helping !
Problem arises too when booting from Bios Boot Manager, which takes me anyway to GRUB and then falls to BusyBox (from all Kernels).
Here is the BootInfo Summary I retrieved via live usb session (since BusyBox wont support commands): https://paste.ubuntu.com/p/PPWVcWkS5B/

Checking in Win, BitLocker seems to be DEactivated (see below). Nevertheless is supposes not to auto-activate Bit Locker when upgrading to 11 (before the win11 update everything was fine).
VolumeType Mount CapacityGB VolumeStatus Encryption KeyProtector AutoUnlock Protection
Point Percentage Enabled Status

OperatingSystem C: 232.83 FullyDecrypted 0 {} Off

Fastboot/hibernate disabled.

oldfred · March 3, 2026, 2:32pm

Looks like default boot is now your Linpus Lite install. And now you only have Ubuntu, so that will never work.
Can you manually select the Ubuntu install shown as boot0002, in UEFI it may just be ubuntu.
If so run this or use Boot-Repair and be sure to choose your Ubuntu install. Boot-Repair may be recommending grub update, but you need the full install (in advanced mode) to have it run efibootmgr to change boot order.

If booted, assumes many defaults from otherwise working install:

sudo grub-install

Best to remove Linpus

man efibootmgr

run this to confirm Linpus still 0000

efibootmgr
sudo efibootmgr -b 0000 -B

granito2526 · March 3, 2026, 2:46pm

Thanks again, and sorry, but Linpus is the bootable USB live session, isn’t it?
When I start without USB, I only get to GRUB (from where I chosse Ubuntu and fail or the still running bloody Windows 11).
From GRUB, I can’t run boot repair or anything else, can I?

tea-for-one · March 3, 2026, 4:08pm

Did the Windows update amend the “Trust” settings in your UEFI configuration?

oldfred · March 3, 2026, 4:38pm

Unusual for Live installer to install an entry into UEFI. USB live systems & installers boot from UEFI boot menu for external device using /EFI/Boot/bootx64.efi, not grub or shim.
Report shows live installer is Ubuntu 24.04.1, not Linpus.
UEFI entrys use GUID, shown in Ubuntu as partUUID and partuuid for 0000 is not shown anywhere else in report.

But if live installer set as default 0000, then you are not booting ubuntu entry.
Can you not choose ubuntu entry in UEFI one time boot menu?

granito2526 · March 5, 2026, 1:04pm

Hello and thank you.’
What explicitly should I look at here?
I disabled secure boot with no sucess.

granito2526 · March 5, 2026, 1:17pm

Hello oldfred and thanks a lot.
I have followed your comments.
I don’t know how to delete the Linpus entry or how to perform boot repair, for example. Because when I start a session from a Live USB, boot repair does not offer any repair options (see report above).
When I select Ubuntu via Boot Manager during start-up, only GRUB starts, followed by an error/BusyBox.

tea-for-one · March 5, 2026, 2:40pm

Uefi Settings > Security > Select UEFI File as Trusted

Boot-repair Line 43 states 0 OS detected
Yet your disk and partitions are found - it’s unusual

Disk nvme0n1: 476.94 GiB, 512110190592 bytes, 1000215216 sectors
Disk identifier: 3C18016C-6841-4B50-97E2-4485CA4261E2
             Start        End   Sectors   Size Type
nvme0n1p1      2048    2203647   2201600     1G EFI System
nvme0n1p2   2203648  510017535 507813888 242.1G Linux filesystem
nvme0n1p3 510017536  510050303     32768    16M Microsoft reserved
nvme0n1p4 510050304  998334463 488284160 232.8G Microsoft basic data
nvme0n1p5 998334464 1000212479   1878016   917M Windows recovery environment

What does still running mean?
Can you access Windows 11?

granito2526 · March 5, 2026, 2:49pm

Sorry, Yes. Windows11 is bootable from Grub / Boot Manager.
I can’t understand how the windows update to 11 could have altered the Ubuntu partition since Grub is running up normally (I use only one HDD).

g-schick · March 5, 2026, 3:29pm

One thing I noticed in your Pastbin post is this insane hexadecimal number after the Windows Boot entry in UEFI section but I do not know if this should be there. It just looks weird to me …

===================================== UEFI =====================================

BIOS/UEFI firmware: V1.27(1.27) from Insyde Corp.
The firmware is EFI-compatible, and is set in EFI-mode for this live-session.
SecureBoot disabled (confirmed by mokutil).
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000,0002,0001,2001,2002,2003
Boot0000* Linpus lite	HD(2,GPT,eed3de8a-acd3-4541-ba17-9014c007d874,0xb8b5a0,0x27a0)/File(\EFI\Boot\grubx64.efi)RC
Boot0001* Windows Boot Manager	HD(1,GPT,c765804e-bb9d-441f-baf6-d3e9de1d12ae,0x800,0x219800)/File(\EFI\Microsoft\Boot\bootmgfw.efi)57494e444f5753000100000088000000780000004200430044004f0042004a004500430054003d007b00390064006500610038003600320063002d0035006300640064002d0034006500370030002d0061006300630031002d006600330032006200330034003400640034003700390035007d00000000000100000010000000040000007fff0400
Boot0002* ubuntu	HD(1,GPT,c765804e-bb9d-441f-baf6-d3e9de1d12ae,0x800,0x219800)/File(\EFI\ubuntu\shimx64.efi)
Boot2001* EFI USB Device	RC
Boot2002* EFI DVD/CDROM	RC
Boot2003* EFI Network	RC

If this is supposed to be there - can somebody explain it to me please?

tea-for-one · March 5, 2026, 3:41pm

Windows updates are proprietary and have been known to change settings in the UEFI firmware, which could also affect dual boot systems.
Your update from Windows 10 to 11 is a major event, so pretty impossible to identify exactly what happened.

Anyway, as you can boot Windows 11 from Grub, I would think that there is hope.
The update may have changed the Acer Trust setting, did you look for it?

yancek · March 5, 2026, 4:58pm

Your Linpus entry points to grubx64.efi which seems odd so do you get the same error when you select that from the BIOS EFI boot menu? I would expect that entry to boot whatever was originally installed on the computer.

granito2526 · March 5, 2026, 5:58pm

Bios. Boot Mode = UEFI
Boot Priority Order = 1. Ubuntu 2. Windows Boot Manager
Priority set to 2. = Windows boots up.
Priority set to 1. = GRUB → failing to BusyBox when selecting Ubuntu

F12 Boot Manager
same as above.
Note: Windows Boot Manager (on /dev/nvme0n1p1)

Security Settings:
I disabled TPM (TCM)State = same: GRUB → failing to BusyBox when selecting Ubuntu
I do not believe clearing TPM (TCM) does something (since Bitlocker etc. was not used). → Or shall I ?

granito2526 · March 5, 2026, 6:02pm

I disabled TPM with no result. Shall I “Clear TPM (TCM)” ?
Secure Boot Mode is set to Standard and not available to change within BIOS.
What more Settings could have been altered by win update in this regard?

tea-for-one · March 5, 2026, 6:06pm

When you reach initramfs, type exit
What happens?

Acer PCs often require a Supervisor/Admin password to access Security settings in the UEFI firmware.

g-schick · March 5, 2026, 6:17pm

As fare as I understand the provided Pastebin boot-repair the boot entry Boot0000 ‘Linpus’ points to sda2. It seems to be the boot partition of the Ubuntu 24.04.1 LTS live usb.

granito2526 · March 5, 2026, 6:56pm

Exiting initramfs brings:
Gave up waiting for root file system device. Common problems:
-Boot args (cat /proc/cmdline)
-Check rootdelay= (..)

Missing modules (cat /proc/modules; ls /dev)
ALERT! UUID=XX does not exist. Dropping to a shell!

NOTE: The shown UUID in the ALERT is not the UUID according to Bios Information.

I cant change Secure Boot Mode even after setting a supervision password.
Is that likely to be the cause?

tea-for-one · March 5, 2026, 7:57pm

No, I don’t think so - Ubuntu generally manages Secure Boot successfully.

Now, let’s try a different approach

Have a look at this topic
Try to boot the Ubuntu kernel directly - option (a)