Hi!
Been using Linux since 2009 but this is the first time I've received the error 'format of the disc image could not be identified. Please set it manually.' when selecting an image to burn using Brasero. I've tried 24.04.02 and 25.04, both ubuntu-mate images yet both give the same error.
What could cause the error and why would I need to set the image manually?
My work around is to use an old DVD with 22.04 on it and keep upgrading from there.
Fubbery
Hi, @Fubbery and welcome to the Ubuntu MATE Community!
wget https://cdimage.ubuntu.com/ubuntu-mate/releases/noble/release/ubuntu-mate-24.04.2-desktop-amd64.iso
#verify iso
sha256sum ubuntu-mate-24.04.2-desktop-amd64.iso
ec1399cf90678c29ee1f80055826b21a3d90f59d50d154e5ea70b1931ce909c9 ubuntu-mate-24.04.2-desktop-amd64.iso
Last time I used a DVD was 10+ years ago so I cannot help there. I always burn the iso to a usb and let my pc boot from the usb to install.
I use Applications | Accessories | Disks to restore the image (.iso) to the usb.
You might want to look at what Google Search AI suggests for
linux disk image repair iso
Apparently, GNOME Disks or Boot Repair can each help you "recover" the ISO image, after which you can create your own image.
I just booted up a questing system on an secondary box of mine that has a DVD writer in it, installed brasero and selected Ubuntu MATE 24.04.2 ISO for writing without issue, and whilst I didn't have a local copy of Ubuntu MATE 25.04 accessible, it had no issue with Xubuntu 25.04 (same installer & will be pretty close), Lubuntu 25.04 (different installer & somewhat different ISO) or Ubuntu Desktop 25.04.
You didn't specify what OS/release you're using, so I didn't have anything specific to try, thus selected the first Ubuntu release I had listed in grub (which is why questing). I didn't write an image as you reporting getting the error on selection.
I doubt there would be an issue if I used a different release though, whilst there is less testing done now on DVD/optical media, its still in the check list for Canonical/Ubuntu Desktop team last I heard. I may not have written an ISO to optical in some time; and that was to explore issues reported after a LTS release, but I'm very aware that optical drives are now getting rather old & thus prone to failure (that doesn't seem to fit your issue though I'll admit!).
Ubuntu hasn't created the ISO for optical install since the 20.04 release though; as there are very few people using it (it's very much optimized now for usage on cloud/disk or flash media)
Sorry, Chris, but that statement is making me "freak out" a bit. My last install involved UM 22.04 from live disk.
Are you suggesting that UM 24.04 and later will not be available for ISO targetted for DVD?
Or are you only referring to the basic UbuntuGNOME or Ubuntu Server versions?
In the kinetic (22.10) cycle the ISOs were altered so all architectures booted the same for a given release; as well as other changes, which included background self-checking of media. A decision was made (based on the tiny number of logged installs) to do that in a manner that suited flash media which allow checking files individually, which is inefficient on storage media such as optical where drives need to alter spin speed.
Optical media should still work, but the self-check & some other decisions are efficient for flash but not optical; this decision was made back in 2020.
No change that I'm aware of has happened since, so there is no change in 24.04 & later, and the change impacted all Ubuntu ISOs, thus flavors too.
When this change occurred; there was a number of bug reports filed, as some older drives handled the media checks much worse than newer drives.. for the older drives the fix is just to wait until self-check completes, as if you try and install or use the system whilst media check is still running, chance of 'timeout' errors increased, these media-timeout errors were sometimes misread by running apps; errors were only appearing on older optical drives though it was noted