I've just bought a Raspberry Pi 3.
I've downloaded the Ubuntu Server image for Raspberry Pi 3 from the official site. I formatted the SD with SDFormatter and wrote the image to the SD with Win32DiskImager.
It initializes OK the first time, I changed the password and then I did an update and rebooted the system with sudo apt update && sudo apt upgrade && sudo reboot
.
After that, the boot process stops at some point with the message:
Raspberry Retry count exceeded; trying again
UBOOT>
I'd really appreciate some help!