So last week I bought the Raspberry Pi 3 model B with the complete Canakit. I installed Ubuntu 16.04 server standard image on the micro sd card with my Windows computer.
I used SF Formatter to format my micro sd card with the Format Size Adjustement option On. I also used Win32DiskImager to write my image on the micro sd card.
Here's the Ubuntu image file that I used: http://www.finnie.org/software/raspberrypi/ubuntu-rpi3/ubuntu-16.04-preinstalled-server-armhf+raspi3.img.xz
The first boot went well. I used that command to upgrade my Raspberry PI:
sudo apt-get update && sudo apt-get dist-upgrade
After that, I rebooted my Raspberry PI and it always got stuck on the u-boot screen. It's like it can't find the OS.
I can add the error code tonight when I get home. I've tried it multiple time and it didn't worked everytime. I also have a Macbook Pro, so if it changed anything I can try to format and write on my micro sd card with it.