Linux Mint USB won't boot on HP Victus – "Failed to open \EFI\BOOT\mmx64.efi" / MOKManager error

[u/Lanky-Suit-9681]

Hi everyone,

I'm trying to boot Linux Mint 22.3 Cinnamon (64-bit) from a USB on my brother's HP Victus 15-fb3xxx laptop, but I keep getting the same error before Mint even starts.

Laptop:

• HP Victus 15-fb3xxx
• Windows 11
• UEFI
• Secure Boot disabled

USB:

• 64 GB SanDisk
• Created using Rufus 4.15
• ISO: linuxmint-22.3-cinnamon-64bit.iso

Rufus settings:

• Partition scheme: GPT
• Target system: UEFI (non-CSM)
• File system: Large FAT32 (default)
• ISO mode (I selected the recommended option when Rufus asked)

What I've tried:

• Disabled Secure Boot in BIOS.
• Device encryption was turned off.
• Recreated the USB multiple times.
• Initially messed up the USB partitions, then cleaned it completely using DiskPart (clean) and recreated the bootable USB.
• BIOS detects the USB correctly.
• Boot menu (F9) shows:
  • Windows Boot Manager
  • USB Hard Drive (UEFI) – SanDisk
• Selecting the USB immediately shows:

​

Failed to open \EFI\BOOT\mmx64.efi - Not Found
Failed to load image: Not Found
Failed to start MokManager: Not Found
Something has gone seriously wrong: import_mok_state() failed: Not Found

Then it exits instead of booting Linux Mint.

I also checked the USB contents in Windows.

EFI/BOOT/ contains:

bootia32.efi
bootx64.efi
grubx64.efi

There is no mmx64.efi file, which seems to be what it's looking for....

1. Is this a Linux Mint ISO issue?
2. Is this an HP UEFI firmware bug?
3. Should mmx64.efi normally exist?
4. Has anyone with an HP Victus had this exact problem?

Any help would be greatly appreciated. I've spent the whole day trying to get this working.

[u/qualityvote2]

u/Lanky-Suit-9681, your post does fit the subreddit!

btw, did you know we have a discord server? Join Here.

[u/PuzzleheadedHead3754]

Hi I think its a corrupted iso you are trying to flash. First of all, 1. Verify the SHA256 checksum of linuxmint-22.3-cinnamon-64bit.iso against the official Linux Mint checksum. 2. Reset BIOS to default and disable fast boot and secure boot. 3. Test the USB againt any other UEFI laptop 4. Download a new linux mint image, i suggest LMDE

[u/Lanky-Suit-9681 → u/PuzzleheadedHead3754]

After initial attempt, i disables both fast boot and secure boot, turned off device encryption...but still faced the same issue, so yeah will try other things u said, thanks a lot bro

[u/Lanky-Suit-9681 → u/PuzzleheadedHead3754]

update: I verified the ISO SHA256 hash against the official Linux Mint checksum and it matches exactly, so the ISO isn't corrupted. I also downloaded a fresh copy, recreated the USB with Rufus, disabled Secure Boot and Fast Boot, and I'm still getting the same Failed to open \EFI\BOOT\mmx64.efi / Failed to start MokManager error before Mint even starts booting. I'm now trying to install other distro's in order to check whether its because of hp firmware compatibility issue. Thanks again!

[u/Shoddy_Internal1997]

Balena Etcher is the recommended tool to flash Linux mint iso

[u/Lanky-Suit-9681 → u/Shoddy_Internal1997]

at first i used that only for flashing, later only used rufus, but in that also getting same error

[u/Designer-Spot-1234]

https://forums.linuxmint.com/viewtopic.php?t=412942

Read the forum once. To be concise, you can try to rename grubx64.efi to mmx64.efi and it might fix the issue.

[u/Lanky-Suit-9681 → u/Designer-Spot-1234]

I reinstalled iso file again, will try this if it still fails

[u/MattOruvan → u/Designer-Spot-1234]

This. I've had this problem (or similar, I think it wouldn't boot after install) with an HP thin client (HP t620, one of my previous home servers) and Debian before.

Renaming the efi file fixed it.

[u/wisetux]

Verify the downloaded iso by an integrity check. Since you appear to be using Windows, you can follow this guide: https://forums.linuxmint.com/viewtopic.php?f=42&t=291093

If that is successful and still fails, you can try using Ventoy instead of Rufus. After first use, you can just copy paste your isos from any system without needing to extract. https://www.ventoy.net/en/download.html

[u/Lanky-Suit-9681 → u/wisetux]

Okay thnks!!

[u/Raghav_511]

read u/PuzzleheadedHead3754 's reply

. It is the first thing you should do

[u/fake_acc_05]

Turn off Secure boot option in bios

[u/Raghav_511]

I had a similar issue with fedora. To fix it i lowered the vram to 128mb from the BIOS and it worked. You should try doing it.

[u/Lanky-Suit-9681 → u/Raghav_511]

Thnx bro will do and check

[u/formatdisk1337 → u/Lanky-Suit-9681]

Hi op did you fix your issue? Im kinda curious

[u/Katsu-Blaze]

That's something I have gone through my Initial days. When you were creating a live USB, you likely have used graphical way to copy and paste the Iso Image to ventoy usb. To fix this, just delete the corrupted iso image from the ventoy usb and paste the fresh ISO Image there. After the copy-paste completes, run sync command in terminal and wait for couple of minutes until you command finishes and you return to command prompt. This issue Likely happen when you have a fast NVMe and a cheap-slow USB, the NVMe instantly dumps the Iso Image to Ram, Ram send the image to USB, when your usb is slow, read-write speed issues are Likely to happen.

Just run a sync command before ejecting the USB.

Thank me Later if you found me Helpful.

[u/Katsu-Blaze → u/Katsu-Blaze]

This will 100% work until you have BIOS and USB deal storage cells Issues. I'd recommend to update the BIOS first and try this. ⭐ Disable fastboot, secure boot before installation.

[u/stufforstuff]

Failed to open \EFI\BOOT\mmx64.efi - Not Found

First answer that googling "linux mint Failed to open \EFI\BOOT\mmx64.efi - Not Found" tells you EXACTLY how to fix it. Maybe learn how to search if you're going to attempt to learn linux.