SD card will not boot

[RasbianSkeptic]

Greetings. I have an SD card with an MBR and FAT32 partition on which I have flashed an iso of KDE Neon. I have also tried using balenaEtcher and the Raspberry PI Imager tool. Regardless of the method of flashing I use, when I try to boot my Pi, I get the screen shown in my photo attachment. I'm not sure what I need to do to correct the problem. I don't understand everything shown on the screen, however, it seems like perhaps the boot files aren't being written to or read from the SD card properly? If anyone has any light they could shed on this problem, I'd really appreciate it. Many thanks!

*I'm using a Pi4 with 4GB RAM.

**UPDATE**
The most helpful thing would be for someone to help me understand why the image won't boot. Is it that the pi can only boot compressed boot images? If I tried flashing with a compressed image, might that have a better result?

[lpsw]

Did you uncompress the image before you flashed the SD card?

[fruitoftheloom]

Greetings. I have an SD card with an MBR and FAT32 partition on which I have flashed an iso of KDE Neon. I have also tried using balenaEtcher and the Raspberry PI Imager tool. Regardless of the method of flashing I use, when I try to boot my Pi, I get the screen shown in my photo attachment. I'm not sure what I need to do to correct the problem. I don't understand everything shown on the screen, however, it seems like perhaps the boot files aren't being written to or read from the SD card properly? If anyone has any light they could shed on this problem, I'd really appreciate it. Many thanks!

*I'm using a Pi4 with 4GB RAM.

Please provide a link to the KDE Neon Operating System you have downloaded as compatible Operating Systems are usually .IMG format.

[RasbianSkeptic]

Did you uncompress the image before you flashed the SD card?

Well actually the iso was provided uncompressed so it just downloaded directly in iso format. Rasp. Pi Imager doesn't allow the use of uncompressed ISOs so I used balenaEtcher however that didn't boot. Then I used dd to write the image onto the SD card. DD exited successfully; however the card still wouldn't boot, yielding the previously shown screen.

[rpdom]

Are you certain this "KDE Neon" OS is compatible with the Raspberry Pi? Can you provide a link to where you downloaded it from?

As fruity says, OS images for Raspberry Pi are usually provided as an img file, not iso. iso is usually for PCs.

[RasbianSkeptic]

Are you certain this "KDE Neon" OS is compatible with the Raspberry Pi? Can you provide a link to where you downloaded it from?

As fruity says, OS images for Raspberry Pi are usually provided as an img file, not iso. iso is usually for PCs.

KDE Neon is an extension of the KDE Plasma environment which is compatible with rasp pi.

[fruitoftheloom]

Are you certain this "KDE Neon" OS is compatible with the Raspberry Pi? Can you provide a link to where you downloaded it from?

As fruity says, OS images for Raspberry Pi are usually provided as an img file, not iso. iso is usually for PCs.

KDE Neon is an extension of the KDE Plasma environment which is compatible with rasp pi.

Yes we do know that, but we are asking what you actually download and from where, or is the .ISO a secret ??