“We are sorry, Calamares closed unexpectedly…”
Had same issue with April 20th .iso
Then with latest.
Was able to install Fedora’s latest KDE.
KDE Neon Plasma never failed me before.
Tried 3 times over past week.
Was wondering… is there a command line that can be used instead?
Not a geek here.
I have the same issue, even I changed Bios settings, and download twice the iso. Nothing seems to work 
I think I will try Fedora KDE instead.
Fedora was nice, but the HPtoolbox that comes preloaded, can’t install the driver for the old printer.
Just sayin’
Which other KDE distro do you recommend? I was thinking on Kubuntu.
Q4OS is nice:
Doesn’t have latest Plasma, but is much smaller .iso and good with older machines.
Btw, welcome to the forum!
Hope you find and friendship here. 
Thank you 
I changed from Linux Mint, my favorite, but I enjoy trying new distros xD I already installed Fedora KDE, let’s see how It works for me. Thanks for The advice.
The current ISO is broken, it seems.
It has already been reported, and devs poked.
EDIT:
Well, Calamares crashes for me when launching it in virt-manager, but it loads on bare metal just fine. I haven’t tried proceeding yet, as I don’t need a fresh OS.
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Thanks for the heads-up!
claydoh I tried a clean install and the error is the same.
The iso has not been updated/rebuilt yet.
I tried today with 20250501-1319.iso and the error remained.
Successfully installed kde neon 
I did it with rufus. You need to set rufus to DD mode when creating a bootable pendrive. It works for me, maybe it will work for you too.
2 Likes
Good for you! 
That’s odd tho.
Never paid attention to that DD mode before…
Have been dabbing around with LMDE 6 and it works great.
Not trying to sway anyone, just sayin’
Will likely go out to try latest KDE Neon 'n see.
@malinowski - inadvertently found the solution!
After downloading latest .iso and copying it with Rufus with its default “recommended”, had the same problem as initially posted here.
Then tried again with Rufus as per @malinowski 's DD suggestion and KDE Neon installed as expected.
Perhaps this was the solution right from the get-go?
If so, why did it always work for me before with Rufus’ default “recommended” .iso?
Maybe KDE Neon should put Rufus with DD option selected?
I don’t know what happened. I always made a pendrive with .iso set in Rufus, but last two isos had the same problem to me. I did it in DD mode for the first time.
Turned out to be a good move.
But if newcomers and even old timers decide to install, they won’t likely know about your discovery.
How can I set that mode on rufus?