Booting with USB flash drive

Hey, I want to switch from CasaOS to umbrelOS but when i use Balena Etcher to Flash my flash drive it makes the flash drive not readable and my bios cant read a unreadable device. I tried to use rufus but it says at 95% that there is an error with the iso image. Does anyone had the same problem and can help me?

I would Verify the hash of image.

Do a reformat of the drive and/or check it for errors.

For some reason, the AMD_x86 iso image doesn’t work correctly and the only way for me to get it onto a usb was using gnome disk image writer using Ubuntu 25.04. Neither the USb creator or Etcher works.

I made an .img file from the iso because the iso is in the wrong format. If you have a linux computer you can convert it by using dd