ISO refused by Multisystem

I don't think it's a bug, it's normal, they publish examples of non supported ISO but the list isn't exhaustive.

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There's some workaround I read on the internet, but I didn't test, as when an ISO is not supported, I try in another ISO burning software.

1. see if there's no space or unsupported characters in the name of the ISO, or in its path. If there are some, rename using "_" instead of the spaces.

2. You must use a USB 2.0, because USB 1.0 is too slow, and USB 3.0 is not supported.
Source: https://lea-linux.org/documentations/MultiSystem

3. Check the other hardware requirements (on the same "source").
Check if you can burn other ISO.

If 1, 2 and 3 are okay, it's simply a technical limitation, not a bug,
but you can try the workaround given in this page (in French): https://forum.ubuntu-fr.org/viewtopic.php?id=1229491

"-Certaines distributions linux ne sont pas supportées par MultiSystem,
cette méthode va vous permettre d'outrepasser cette limite.
Dans cet exemple nous allons ajouter une version de Debian bien pratique,
car elle intègre tous les firmwares, et en plus elle est multi-architectures."

Tip: Try to use Google translate if you can't read French.

This bug has been posted in 2016-06-08 4 years ago.

Points 1, 2 and 3 are OK

I abandoned the use of Multi System because it was too unstable after adding / removing a lot of ISO. (in order to have up to date versions)

Now I keep just a small amount of usb keys for the system I mainly use and install, and I use spare keys for testing.

And the UEFI generalization did not help : on every single computer I Wanted to test, I have a different version of UEFI, with different implementation of the "security" features leading to W10 being the only OS install able on some machines...

BTW, I am french....

@Elbarbudo This is interesting, because I noticed also unstability after removing/readding lots of ISO. I though my disk was guilty or not working properly.

What kind of unstability did you have? What kind of messages or behaviours?

("If you can't read French" is for everyone reading this thread.)

I finally tested some workarounds, and managed to make some unsupported ISO to work.

I mean "USB 2" port (not stick), in my first message. I re-read it, and it was not clear at all that I mean this. By the way, I don't know if this limitation still apply, or if they fixed it. Just mentioning that for people who could find this thread via a search engine.

@PERCE-NEIGE Sorry, but the original bug has been submitted 4 years ago and I don't remember exactly what happened.
The "ISO not supported" incident triggered my abandon of MultiSystem.

As far as I remember, on each new major distribution I had to test, I needed to re-create my multisystem Usb stick, to make sure it's work.

At this time, there was an application called "Multisystem" used to manage the Usb stick, but I don't find it now.